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Using the method of non‐reactive sintering of nanocrystalline powders, highly transparent samples of optical ceramics based on solid solutions of yttrium‐scandium aluminum garnets containing 50 at.% scandium in the dodecahedral position and doped with erbium (1 at.%) and ytterbium (0–49 at.%) cations (YSAG:Yb:Er) were produced. The influence of Yb3+ concentration on the crystal lattice parameter, density, refractive index, stability of YSAG:Yb:Er solid solutions during high‐temperature sintering, thermal conductivity, optical transmittance and absorption coefficients in the wavelength range from 200 to 1100 nm, as well as Stokes and anti‐Stokes luminescence, was determined. The revealed patterns make it possible to fine‐tune the physical and chemical characteristics of ceramics for the design of composite laser materials. [ABSTRACT FROM AUTHOR]

In this study, we propose novel three-layer composite scintillators designed for the simultaneous detection of different ionizing radiation components. These scintillators are based on epitaxial structures of LuAG and YAG garnets, doped with Ce3+ and Sc3+ ions. Samples of these composite scintillators, containing YAG:Ce and LuAG:Ce single crystalline films with different thicknesses and LuAG:Sc single crystal substrates, were grown using the liquid phase epitaxy method from melt solutions based on PbO-B2O3 fluxes. The scintillation properties of the proposed composites, YAG:Ce film/LuAG:Sc film/LuAG:Ce crystal and YAG:Ce film/LuAG:Ce film/LuAG:Sc crystal, were investigated under excitation by radiation with α-particles from a 239Pu source, β-particles from 90Sr sources and γ-rays from a 137Cs source. Considering the properties of the mentioned composite scintillators, special attention was paid to the ability of simultaneous separation of the different components of mixed ionizing radiation containing the mentioned particles and quanta using scintillation decay kinetics. The differences in scintillation decay curves under α- and β-particle and γ-ray excitations were characterized using figure of merit (FOM) values at various scintillation decay intensity levels (1/e, 0.1, 0.05, 0.01). [ABSTRACT FROM AUTHOR]

A Yb3+‐doped Gd3Al2Ga3O12 garnet (GAGG) Boltzmann thermometer is prepared and studied in this work. Due to the Boltzmann distribution of the population of Stark sublevels of Yb3+, the photoluminescence peaks of Yb3+ in the wavelength range of 950–1000 and 1000–1050 nm exhibit opposite temperature dependencies, which makes the luminescence intensity ratio (LIR) of two Yb3+ peaks work as a luminescence thermometer with a relative sensitivity of 1.6% K−1 at 200 K. It is worth nothing that this LIR value still follows the Arrhenius model at temperatures as low as 200 K. In these results, it is suggested that Yb3+‐doped GAGG thermometer can achieve high sensitivity for accurate temperature measurements. In addition, the accurate position of various Stark sublevels of Yb3+ in GAGG is obtained for the first time. In this work, it is confirmed that the Yb3+‐doped GAGG thermometer exhibits potential applications in the fields of microelectronics and biology. [ABSTRACT FROM AUTHOR]

The novel orange‐red light‐emitting garnet‐type phosphors Li3Bi3Te2O12:xSm3+ (0.005 ≤ x ≤ 0.25) were first synthesized using the high‐temperature solid‐state reaction method. The phase structure was recorded with XRD. Raman spectroscopic analysis was conducted for the first time to extract detailed structural insights of the tellurate garnet Li3Bi3Te2O12:Sm3+. The characteristics of the obtained compounds were investigated, including particle morphology, elemental mapping, diffuse reflection spectra, excitation and emission spectra, thermal stability, chromaticity coordinates according to the Commission International del′Eclairage, and color purity. The Li3Bi3Te2O12:Sm3+ phosphor could be effectively excited by 406 nm irradiation, and four sharp peaks were presented. The dominant peaks are located at 613 and 653 nm, corresponding to the typical transition of Sm3+ ions at 4G5/2→6H7/2 and 4G5/2→6H9/2, respectively. The phosphors present a regular concentration quenching trend, with an optimum Sm3+ doping concentration of 0.02. Impressively, the product demonstrates remarkable thermal stability by maintaining an emission intensity of 93% at a working temperature of 423 K. Additionally, the thermal quenching temperature (T0.5) surpasses 480 K. The lighting performance of the white light‐emitting diode fabricated using Li3Bi3Te2O12:0.02Sm3+ phosphor has been found to be exceptional, characterized by a high color rendering index (Ra = 90) and a low correlated color temperature (CCT = 5122 K). The electroluminescent spectrum of the red light‐emitting diode device fabricated by Li3Bi3Te2O12:0.02Sm3+ overlapped well with the absorption spectra of the phytochromes, suggesting its potential for plant cultivation light source. In conclusion, considering all these photoluminescent properties mentioned above, Li3Bi3Te2O12:Sm3+ phosphor can be regarded as a promising material for daily illumination and plant cultivation LEDs. [ABSTRACT FROM AUTHOR]

Phosphor‐converted light‐emitting diodes (pc‐LEDs) are efficient and cost‐effective ultrabroadband light sources for miniaturizing various optical systems, but they exhibit poor optical performance due to the lack of efficient near‐infrared (NIR) phosphors with a wide spectral coverage of 700−1100 nm. Although germanate oxides are a promising class of host materials for Cr3+ to generate broadband NIR light, the preferred formation of [CrO4]4− and the high vapor pressure of Ge element cause these Cr3+ activated phosphors to suffer from low internal quantum efficiency (IQE) and poor thermal stability. Here, highly efficient (IQE > 90%) and thermally stable broadband NIR emission of Cr3+ in the germinate garnet Ca2LuMgScGe3O12 (CLMSG) are obtained by exploiting a two‐step sintering method to achieve full reduction of Cr4+ to Cr3+. Further, efficient energy transfer from Cr3+ to Yb3+ is leveraged to significantly improve the emission intensity of CLMSG:Cr3+ in the shortwave infrared range of 900−1100 nm. Finally, an ultrabroadband NIR pc‐LED with a high NIR conversion efficiency (21.5%@10 mA) and high NIR power (116.4 mW@350 mA) is demonstrated to verify the strong capability of CLMSG:Cr3+, Yb3+ in blue‐to‐NIR light conversion. The results open up new ways to realize efficient ultrabroadband NIR‐emitting materials. [ABSTRACT FROM AUTHOR]

Plasma etching is a crucial step in semiconductor manufacturing. High cleanliness and wafer‐to‐wafer reproducibility in the etching chamber are essential in order to successfully achieve nanometer‐sized integrated functions on the wafer. The trend toward the application of more aggressive plasma compositions leads to higher demands on the plasma resistance of the materials used in the etching chamber. Due to its excellent etch resistance, yttrium aluminum garnet Y3Al5O12 (YAG) is starting to replace established materials like SiO2 or Al2O3 in this kind of application. In this study, reactive spark plasma sintering (SPS) was used to manufacture highly dense YAG ceramics from the respective oxides. In addition, yttrium was replaced with heavier lanthanoids (Er, Lu), intending to investigate the role of the A‐site cation in the garnet type structure on the plasma erosion behavior. The produced materials were exposed to fluorine‐based etching plasmas mimicking the conditions in the semiconductor manufacturing apparatus and the erosion behavior was characterized by atomic force microscopy (AFM), secondary ion mass spectrometry (SIMS), transmission electron microscopy (TEM), and profilometry. The induced chemical gradient in the samples is limited to a few nanometers below the surface, which makes its characterization challenging. For advanced analysis, we developed a correlative characterization method combining SIMS and scanning TEM (STEM)–energy‐dispersive spectroscopy (EDS) enabling us to examine the structural and chemical changes in the reaction layer locally resolved. In the case of lanthanoid aluminates, an altered reaction layer and reduced fluorine penetration compared to YAG were found. However, a correlation between the characteristics of the induced chemical gradient and the determined physical erosion rates was not evident. [ABSTRACT FROM AUTHOR]

[Display omitted] • Definition of the thermal structure of the Brazilian SCLM using geothermobarometers. • Ultra-alkaline silicate metasomatism involved in deep Brazilian SCLM. • Shallow portion of Brazilian SCLM affected by silicate metasomatism. • Definition of hotter SCLM under Três Ranchos than Osvaldo França/Canastra. The thermal structure and chemical composition of the subcontinental lithospheric mantle beneath the Alto Paranaíba Igneous Province defined by the major and trace element compositions of garnet and clinopyroxene xenocrysts and mantle peridotite xenoliths entrained in the Cretaceous Três Ranchos kimberlite. Estimated temperatures and pressures indicate a typical cratonic geotherm, with a surface heat flow of ∼ 40 mW/m2 slightly hotter than that at the São Francisco Craton margin (35–36 mW/m2), suggesting lateral heterogeneities in the geothermal gradients. A deep mantle portion (160 km) is recorded by a lherzolite xenolith (5 GPa and 1200 °C). This portion has undergone pervasive interstitial melt percolation of an ultra-alkaline silicate melt and late injection of small silicate melt fractions such as the host carbonated kimberlite. This pervasive migration extended into shallower SCLM sectors at 124–100 km (3.9–3.1 GPa and ∼ 940–810 °C) as evidenced by metasomatized (±phlogopite) peridotite identified by sinusoidal REE garnet compositions. This portion is apparently intercalated at 120–110 km depth (3.7–3.3 GPa and ∼ 850 °C) with strongly depleted peridotites showing garnet and clinopyroxene compositions extremely impoverished in moderately incompatible elements, as a result of extreme ancient, melt extraction. Atop the metasomatized and depleted peridotites, at 100 km depth, a layer of fertile lherzolite is identified by garnet xenocrysts, with 'normal', HREE-enriched, steadily fractionated LREE-depleted patterns. Combining our data with those of the Osvaldo França SCLM points to the occurrence of a deeper sector (>100 km depth beneath Trȇs Ranchos) originally formed by extremely depleted peridotites, successively metasomatized by ultra-alkaline melts; and a shallower sector of the São Francisco craton composed of fertile lherzolites unrelated to ultra-alkaline magmatism. Similar fertile lherzolites are found in the uppermost sectors of the Siberian and Kaapval SCLM, suggesting that they may be a ubiquitous, primary feature, possibly related to the stabilization of the Archean cratons. [ABSTRACT FROM AUTHOR]

The scientific community is exploring novel all-solid-state batteries (ASSBs) as a substitute for conventional lithium-ion batteries with liquid electrolytes. These ASSBs possess several attractive advantages, including improved safety, extended temperature range, and improved energy density. Solid-state electrolytes (SSE) have become significant parts of ASSBs. For example, garnet-type Li7La3Zr2O12 (LLZO) SSE has shown promise among the various forms of SSEs. LLZO demonstrates ionic conductivity of 10−3 to 10−4 S/cm and remarkable chemical durability in combination with lithium metal. Because of these qualities, LLZO is a good option for solid-state Li-metal batteries. Various advancements have been made in garnet-type SSEs and ASSBs since the discovery of LLZO in 2007, resulting in enhanced electrochemical durability and energy density. The advantages of LLZO include durability and safety under elevated temperatures, high-temperature stability, and safety of garnet-type electrolytes. This review article examines current developments in garnet-type LLZO electrolytes, considering experimental research and theoretical findings. We discuss the synthetic methodology, modifications, the robustness of these garnet-based electrolyte materials, novel blueprints for nanostructures, understanding of the electrolyte decomposition pathway, and routes to overcome the electrolyte decomposition pathway with regard to LZZO. Additionally, battery architectures and integrations are explored. The review provides a comprehensive outlook for garnet-based LLZO electrolyte research, focusing on its applications in different solid-state battery concepts, such as Li-ion, Li-S, and Li-air batteries. It highlights the opportunities and perspectives that garnet-type LLZO electrolytes offer, serving as a roadmap for future advancements in SSEs and batteries. [ABSTRACT FROM AUTHOR]

Cr3+‐doped phosphors are highly recognized in various fields for their remarkable luminous efficiency and spectral flexibility, including modern agriculture and horticulture. However, the shortage of suitable Cr3+‐doped phosphors for far‐red LED devices has inhibited their popularization in plant lighting. Herein, an innovative Cr3+‐doped phosphor Ca2YAl3Ge2O12:Cr3+ (CYAG:Cr3+), achieving a broad far‐red emission at 770 nm upon 450 nm blue light excitation is designed. The optimal CYAG:Cr3+ phosphor exhibits a high internal quantum yield of 78.2% and low thermal‐quenching behavior of 85%@373 K. Thus, the fabricated phosphor‐converted LEDs (pc‐LEDs) for plant far‐red lighting have a high output power of 33.3 mW and photovoltaic conversion efficiency of 11.5% at 100 mA. The potential of CYAG:Cr3+ in plant lighting is assessed by supplementing the far‐red lighting of Italian lettuce with fabricated pc‐LEDs, and the biomass of Italian lettuce is significantly increased by 33%. The successful development of CYAG:Cr3+ phosphors provides a high‐quality option for plant far‐red light devices and further stimulates the development of new Cr3+‐doped plant‐lighting phosphors. [ABSTRACT FROM AUTHOR]

In this study, we conducted an extensive investigation into broadband near-infrared luminescence of Cr3+-doped Ca3Y2Ge3O12 garnet, employing first-principles calculations within the density functional theory framework. Our initial focus involved determining the site occupancy of Cr3+ activator ions, which revealed a pronounced preference for the Y3+ sites over the Ca2+ and Ge4+ sites, as evidenced by the formation energy calculations. Subsequently, the geometric structures of the excited states 2E and 4T2, along with their optical transition energies relative to the ground state 4A2 in Ca3Y2Ge3O12:Cr3+, were successfully modeled using the ΔSCF method. Calculation convergence challenges were effectively addressed through the proposed fractional particle occupancy schemes. The constructed host-referred binding energy diagram provided a clear description of the luminescence kinetics process in the garnet, which explained the high quantum efficiency of emission. Furthermore, the accurate prediction of thermal excitation energy yielded insights into the thermal stability of the compound, as illustrated in the calculated configuration coordinate diagram. More importantly, all calculated data were consistently aligned with the experimental results. This research not only advances our understanding of the intricate interplay between geometric and electronic structures, optical properties, and thermal behavior in Cr3+-doped garnets but also lays the groundwork for future breakthroughs in the high-throughput design and optimization of luminescent performance and thermal stability in Cr3+-doped phosphors. [ABSTRACT FROM AUTHOR]

A collection of Hellenistic–Roman glyptics, kept at the Regional Archaeological Museum "Paolo Orsi" (Syracuse, Italy), was investigated in situ with portable Raman spectroscopy with the aim of assessing the viability of this approach, not only for the immediate identification of the gemstones but also for a more in‐depth successive data treatment. At the same time, a corroboration of the autoptic identification of the materials, both archeological and belonging to historical collections, was looked for in order to verify and potentially correct what reported in the museum catalogue. Actually, most of the identifications could be confirmed, the glyptics being mainly made of chalcedony. Other materials found were garnet, glass, and amber. The larger group of chalcedony Raman spectra was subjected to principal components analysis treatment that, after appropriate pretreatment, resulted successful in separating spectra with higher or lower contribution of the band due to the presence of moganite and SiOH bonds. The garnet spectra were instead subjected to quantitative study to identify the main end member. Both the quick identifications and the more detailed studies on chalcedonies and garnets were achieved thanks to the nondestructive and noninvasive investigation, directly in situ, with no sample preparation and minimal interference with the museum's activities. [ABSTRACT FROM AUTHOR]

YAG:Ce and LuAG:Ce ceramics are widely used as scintillator materials that convert high‐energy radiation into visible light. For the practical application of such compounds, short decay times are a necessity. One way of shortening the existing decay times even more is to change the local environment of emitting ions by means of doping the matrix with additional elements, for example, boron or magnesium. Furthermore, boron ions also can help absorb gamma rays more efficiently, therefore improving overall applicability. Due to the aforementioned reasons, YAG and LuAG ceramics doped with cerium, boron, and magnesium were synthesized. Initial amorphous powders have been obtained by means of sol–gel synthesis and pressed into pellets under isostatic pressure and finally calcinated to form crystalline ceramics. The effects of boron and magnesium doping on the morphological, structural, and luminescence properties were investigated. The key results showed that doping with boron has indeed shortened the decay times of the garnet pellets. Overall, boron doping of ceramics is a relatively new research area; however, it is rather promising as it helps both to improve the luminescence properties and to increase particle growth rate. [ABSTRACT FROM AUTHOR]

In this study, we propose novel three-layer composite scintillators designed for the simultaneous detection of different ionizing radiation components. These scintillators are based on epitaxial structures of LuAG and YAG garnets, doped with Ce3+ and Sc3+ ions. Samples of these composite scintillators, containing YAG:Ce and LuAG:Ce single crystalline films with different thicknesses and LuAG:Sc single crystal substrates, were grown using the liquid phase epitaxy method from melt solutions based on PbO-B2O3 fluxes. The scintillation properties of the proposed composites, YAG:Ce film/LuAG:Sc film/LuAG:Ce crystal and YAG:Ce film/LuAG:Ce film/LuAG:Sc crystal, were investigated under excitation by radiation with α-particles from a 239Pu source, β-particles from 90Sr sources and γ-rays from a 137Cs source. Considering the properties of the mentioned composite scintillators, special attention was paid to the ability of simultaneous separation of the different components of mixed ionizing radiation containing the mentioned particles and quanta using scintillation decay kinetics. The differences in scintillation decay curves under α- and β-particle and γ-ray excitations were characterized using figure of merit (FOM) values at various scintillation decay intensity levels (1/e, 0.1, 0.05, 0.01).

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Cr3+‐activated Gd3Ga5O12 garnet (GGG:Cr3+) near‐infrared (NIR) phosphors have shown promising applications in regulating plant growth. However, the low external quantum efficiency (EQE) results in a wall‐plug efficiency (WPE) of phosphor‐converted light‐emitting diodes (pc)‐LEDs of only ≈15%. Herein, an easy strategy to improve the luminescent properties of the GGG:Cr3+ phosphor is reported. Through optimization of the synthesized technology, the EQE is enhanced to 43.6%. Remarkably, the fabricated pc‐LEDs achieve a WPE as high as 34.3%. These results demonstrate a significant advancement in the development and applications of NIR phosphor materials and NIR pc‐LED devices. [ABSTRACT FROM AUTHOR]

Garnet‐type electrolytes demonstrate promising prospects in the field of solid‐state lithium batteries owing to their superior ionic conductivity and high (electro)chemical stability toward Li metal, whereas the critical issue of Li dendrite growth and even infiltration throughout garnets limits their practical applications. Herein, a hybrid interlayer consisting of Li3Bi alloy embedded in antiperovskite‐type Li3OCl matrix is in situ constructed at Li/Li6.75La3Zr1.75Ta0.25O12 interface by taking the conversion reaction of BiOCl with Li metal. The lithiophilic nature of such interlayer enables an intimate contact of garnet against Li metal, guaranteeing a dramatically reduced interfacial resistance of 27 Ω cm2. In addition, the inside electron‐conducting Li3Bi nanoparticles homogenize the interfacial potential distribution, while the outside ion‐conducting Li3OCl matrix with a bandgap of 5.06 eV blocks electron tunneling from Li bulk. Profiting from such synergistic effect, the resultant Li symmetric cell displays a high critical current density of 1.1 mA cm−2, along with an ultralong cycling life of 1000 h at 0.5 mA cm−2. Furthermore, the corresponding solid LiNi0.6Co0.2Mn0.2O2/Li cell delivers a high cycling stability for 150 times accompanied by a capacity retention of 82%. This study puts forward a potential solution for construction of functional layers at Li/garnet interfaces by making use of in situ conversion reaction. [ABSTRACT FROM AUTHOR]

The preparation of gadolinium aluminium garnet (GAG) doped with Cr3+ ions (Cr: GAG) was carried out using the sol–gel technique, followed by sintering at 1100 °C. X-ray diffraction characterization was performed to investigate the effects of Cr3+ doping on the GAG phase. The results revealed that Cr3+ doping induced strain in GAG, leading to a phase effect and an increase in crystallite size. Field emission scanning electron microscopy was utilized to observe the particle size, morphology, and a comparison of crystallite size with particle size. Fourier transform infrared spectroscopy was used to confirm the interaction between metal and oxygen in the lattice and assess the material's composition. UV spectroscopy and fluorescence spectra were employed to comprehensively study the optical characteristics of Cr: GAG. Chromaticity coordinates, correlated color temperature, and color rendering index were explored at 282 nm excitation. Decay curve analysis revealed that the material's lifetime increased with an increase in the Cr3+ doping concentration in GAG. Fluorescence spectra exhibited multiple peaks, indicating multicolor emission and suggesting the potential for creating efficient white light sources using Cr: GAG. Overall, these findings highlight the potential of Cr3+ doping in GAG for tuning the optical properties and creating novel light-emitting energy- efficient materials with promising applications. [ABSTRACT FROM AUTHOR]

A comprehensive mineralogical and geochemical characterization (XRF, ICP-MS, SEM-EDS, SIMS methods) of garnetites and their protoliths from the Marun-Keu complex (Polar Urals), one of the key objects in understanding the evolution of the Uralian Orogen, is presented. Garnetites and their protoliths from the Marun-Keu complex, Polar Urals, a key locality for understanding the evolution of the Uralian Orogen, are described mineralogically and geochemically using XRF, ICP-MS, SEM-EDS and SIMS methods. Ultramafic (in most cases) and mafic rocks are understood as protoliths for garnetites. A general trend for garnetites is an increase in total REE concentration relative to that of their protoliths. All the analyzed garnetites display a considerable decrease in Cr, Ni and Co. V concentration in the garnetites is also lower than that of the protoliths, though not so markedly. Garnets from garnetites evolving after peridotites generally exhibit elevated (relative to garnets from garnetites evolving after mafic rocks, such as porphyrites) Prp and lowered Alm content, which seems to be due to high Mg concentration in the protolith. In garnetites after peridotites a garnet exhibiting an uncommon non-differentiated REE spectrum with a considerable positive Eu-anomaly was found, which could be due to the inheritance of a REE spectrum by garnet from a precursor mineral, in this case plagioclase. Slyudyanaya Gorka garnetites were probably formed from mafic and ultramafic rocks in oceanic crust, which migrated to higher levels of the section under the influence of the crustal fluid flowing along fracturing zones.

In this study, we conducted an extensive investigation into broadband near-infrared luminescence of Cr3+-doped Ca3Y2Ge3O12 garnet, employing first-principles calculations within the density functional theory framework. Our initial focus involved determining the site occupancy of Cr3+ activator ions, which revealed a pronounced preference for the Y3+ sites over the Ca2+ and Ge4+ sites, as evidenced by the formation energy calculations. Subsequently, the geometric structures of the excited states 2E and 4T2, along with their optical transition energies relative to the ground state 4A2 in Ca3Y2Ge3O12:Cr3+, were successfully modeled using the ΔSCF method. Calculation convergence challenges were effectively addressed through the proposed fractional particle occupancy schemes. The constructed host-referred binding energy diagram provided a clear description of the luminescence kinetics process in the garnet, which explained the high quantum efficiency of emission. Furthermore, the accurate prediction of thermal excitation energy yielded insights into the thermal stability of the compound, as illustrated in the calculated configuration coordinate diagram. More importantly, all calculated data were consistently aligned with the experimental results. This research not only advances our understanding of the intricate interplay between geometric and electronic structures, optical properties, and thermal behavior in Cr3+-doped garnets but also lays the groundwork for future breakthroughs in the high-throughput design and optimization of luminescent performance and thermal stability in Cr3+-doped phosphors.

Trivalent europium (Eu3+) doped phosphors usually radiate orange or red light owing to distinct transitions from the 5D0 excited level to the ground states of 7F1 and 7F2. However, Eu3+ activated phosphors with a dominant deep‐red emission due to 5D0→7F4 transition are relatively rare. In this work, the synthesis and photoluminescence properties of Ca3Al2Ge3O12:Eu3+ deep‐red phosphor with an intense 5D0→7F4 transition are reported. Irradiating this new garnet phosphor with 394 nm near‐ultraviolet light generates a dominant deep‐red emission band centered at 707 nm. The phosphor has a high internal quantum efficiency of 98.4% and excellent luminescence thermal stability, maintaining 78.8% of the room temperature emission intensity at 150 °C. Based on the unique spectral feature of this new compound, a phosphor‐converted deep‐red LED prototype device is fabricated, producing an output power of 27.3 mW with a photoelectric conversion efficiency of 4.0% at 200 mA. Plant growth experiments are also conducted to demonstrate the obvious positive effects of the fabricated deep‐red LED on plant growth, further indicating that the as‐prepared Ca3Al2Ge3O12:Eu3+ deep‐red phosphor can act as a promising luminescence converter for plant growth LED bulbs. [ABSTRACT FROM AUTHOR]

The validity of prediction methods for garnet lattice parameters was tested, and a modified model with best fit to a lattice parameter database with over 1000 garnet compositions was developed. The lattice parameter predictions were used in Shannon and Fischer's model to predict garnet refractive indices. The predictions were compared to refractive index measurements reported for 143 garnet compositions. After calibration of electron overlap factors used in the model, the average prediction error was 1.13%. Sources of error in the models are discussed, as well as applications of the predictive methods. [ABSTRACT FROM AUTHOR]

The validity of prediction methods for garnet lattice parameters was tested, and a modified model with best fit to a lattice parameter database with over 1000 garnet compositions was developed. The lattice parameter predictions were used in Shannon and Fischer's model to predict garnet refractive indices. The predictions were compared to refractive index measurements reported for 143 garnet compositions. After calibration of electron overlap factors used in the model, the average prediction error was 1.13%. Sources of error in the models are discussed, as well as applications of the predictive methods. [ABSTRACT FROM AUTHOR]

Gadolinium aluminum garnets (GAG) in recently times are examined for their application in enhancing the efficiency of photonic devices. A sequence of samples for gadolinium aluminum garnet (Gd3Al5O12) was synthesized effectively using the sol–gel method. The prepared sample was sintered at various temperatures, but at 1100 °C pure phase developed was identified by X-ray diffraction, and luminescence properties were studied by several characterizations such as Fourier transform infrared spectroscopy (FTIR), UV–Vis spectroscopy, and fluorescence spectroscopy. XRD gave the confirmation of the phase formation of GAG, and analyses of FTIR were also coordinated with XRD results. Emission spectra corresponding to 6I7/2,6D9/2, and 6G7/2 energy transition from state 8S7/2 were determined for three UV excitations, i.e., 256 nm, 290 nm, and 391 nm, and show mixed color components on the chromaticity diagram. [ABSTRACT FROM AUTHOR]

Lithium lanthanum zirconium oxide (LLZO) garnet is a solid‐state lithium ion conducting electrolyte promising all‐solid‐state batteries (ASSB) with high charge rates and good energy density due to its chemical stability against lithium metal anodes. LLZO has a high room temperature Li ion conductivity of ∼0.1–1 mS/cm in its cubic phase, but the stability of the cubic phase and ionic conductivity are highly sensitive to lithium stoichiometry. Stabilizing agents such as aluminum oxide and excess lithium are needed to preserve the cubic phase and compensate for lithium volatility. With the range of the end LLZO products spanning powders, porous membranes to dense membranes combined with sintering/calcination that often exceeds 1000°C, it is challenging to maintain an ideal lithium content given its high volatility from a single base powder. This study was designed to elucidate the sensitivities of aluminum doped LLZO powder synthesis and processing along its path to being utilized in a ceramic‐manufacturing optimized ASSB. By utilizing thermogravimetric analysis in conjunction with in situ X‐ray diffraction analysis of solid‐state LLZO synthesis, it was discovered that the sensitivity of the LLZO cubic phase to lithium volatility can be reduced via early incorporation of excess lithium carbonate during initial phase formation in direct combination with controlled surface‐to‐volume ratios of the powders. Isostatically pressed powders of our LLZO sintered at 1100°C for 2 h showed RT ionic conductivity of 0.3–0.4 mS/cm measured via electrochemical impedance spectroscopy, and an improvement in microstructural uniformity with lowered porosity. The improved suppression of lithium volatilization has important implications for the scalable production of LLZO powders and assembly of ASSBs. [ABSTRACT FROM AUTHOR]

The impact of liquid electrolyte soaking on the interfacial resistance between the garnet-structured Li7La3Zr2O12 (LLZO) solid electrolyte and metallic lithium has been studied. Lithium carbonate (Li2CO3) formed by inadvertent exposure of LLZO to ambient conditions is generally known to increase interfacial impedance and decrease lithium wettability. Soaking LLZO powders and pellets in the electrolyte containing lithium tetrafluoroborate (LiBF4) shows a significantly reduced interfacial resistance and improved contact between lithium and LLZO. Raman spectroscopy, X-ray diffraction, and soft X-ray absorption spectroscopy reveal how Li2CO3 is continuously removed with increasing soaking time. On-line mass spectrometry and free energy calculations show how LiBF4 reacts with surface carbonate to form carbon dioxide. Using a very simple and scalable process that does not involve heat-treatment and expensive coating techniques, we show that the Li-LLZO interfacial resistance can be reduced by an order of magnitude.

A new type of high-entropy rare-earth iron garnet ceramic structure (Gd 0.2 Dy 0.2 Er 0.2 Y 0.2 RE 0.2) 3 Fe 5 O 12 (RE = Sm, Eu, Tm, Yb) powders were synthesised using a solid-phase method. In addition, the microstructure and magnetic properties of the (Gd 0.2 Dy 0.2 Er 0.2 Y 0.2 RE 0.2) 3 Fe 5 O 12 (RE = Sm, Eu, Tm, Yb) powders were evaluated. The (Gd 0.2 Dy 0.2 Er 0.2 Y 0.2 RE 0.2) 3 Fe 5 O 12 (RE = Sm, Eu, Tm, Yb) ceramics presented garnet crystal structure (Ia-3d), and their lattice parameters ranged between 12.3921 and 12.3644 Å. Moreover, the saturation magnetisation (M s) and coercivity (H c) of the ceramics ranged between 12.29 and 13.27 emu/g and between 18.46 and 19.87 Oe, respectively. The M s and H c values of the samples were comparable, indicating that magnetism of high-entropy rare-earth iron garnet ceramic can be fine-tuned by customising their composition. The magnetic properties of high-entropy rare-earth iron garnet ceramics have not yet been elucidated; however, previous studies have demonstrated that high-entropy rare-earth iron garnet ceramics present unique magnetism. [ABSTRACT FROM AUTHOR]

A solid‐state battery with a lithium‐metal anode and a garnet‐type solid electrolyte has been widely regarded as one of the most promising solutions to boost the safety and energy density of current lithium‐ion batteries. However, lithiophobic property of garnet‐type solid electrolytes hinders the establishment of a good physical contact with lithium metal, bringing about a large lithium/garnet interfacial resistance that has remained as the greatest issue facing their practical application in solid‐state batteries. Herein, a melt‐quenching approach is developed by which varieties of interfacial modification layers based on metal alloys can be coated uniformly on the surface of the garnet. It is demonstrated that with an ultrathin, lithiophilic AgSn0.6Bi0.4Ox coating the interfacial resistance can be eliminated, and a dendrite‐free lithium plating and stripping on the lithium/garnet interface can be achieved at a high current density of 20 mA cm−2. The results reveal that the uniform coating on the garnet surface and the facile lithium diffusion through the coating layer are two major reasons for the excellent electrochemical performances. The all‐solid‐state full cell consisting of the surface modified garnet‐type solid electrolyte with a LiNi0.8Mn0.1Co0.1O2 cathode and a lithium–metal anode maintains 86% of its initial capacity after 1000 stable cycles at 1 C. [ABSTRACT FROM AUTHOR]

Mn 3 Al 2 Ge 3 O 12 is a member of the garnet family of compounds, A 3 B 2 (CO 4 ) 3 , whose magnetic properties are affected by a high degree of geometrical frustration. The magnetic frustration is at the origin of the intriguing magnetic properties that these materials exhibit, such as a long range hidden order derived from multipoles formed from 10-spin loops in the gadolinium gallium garnet, Gd 3 Ga 5 O 12 . Mn 3 Al 2 Ge 3 O 12 garnet is isostructural to the thoroughly investigated Gd garnets, Gd 3 Ga 5 O 12 and Gd 3 Al 5 O 12 . Moreover, in Mn 3 Al 2 Ge 3 O 12 , the Heisenberg-like Mn 2 + magnetic ions ( L = 0) are also arranged in corner sharing triangles that form a hyperkagomé structure. The identical crystallographic structures and similar Heisenberg-like behaviour of the magnetic ions make manganese aluminium germanium garnet the closest compound to the gadolinium garnets in its magnetic properties. Here, we report, for the first time, the growth of a large, high quality single crystal of the Mn 3 Al 2 Ge 3 O 12 garnet by the floating zone method. X-ray diffraction techniques were used to characterise and confirm the high crystalline quality of the Mn 3 Al 2 Ge 3 O 12 crystal boule. Temperature-dependent magnetic susceptibility measurements reveal an antiferromagnetic ordering of the Mn 2 + ions below T N = 6.5 K. The high quality of the single crystal obtained makes it ideal for detailed investigations of the magnetic properties of the system, especially using neutron scattering techniques. [ABSTRACT FROM AUTHOR]

Near‐infrared (NIR) spectroscopy based on phosphor‐converted light‐emitting‐diode (pc‐LED) has promising applications in food quality analysis, security monitoring, medical diagnosis, and bioimaging fields, stimulating the demand of developing NIR phosphors with high‐performance. Herein, a highly efficient and thermally robust Ca3MgHfGe3O12:Cr3+ NIR phosphor is discovered, which exhibits a broadband NIR emission (λem = 800 nm) covering 700 to 1100 nm region with an internal quantum efficiency as high as 90.7% when excited by 460 nm blue light. Moreover, the emission intensity at 423 K retains 84.5% of that at room temperature. The highly efficient and thermally robust luminescence of this material is mainly ascribed to the ultrawide bandgap of host, extremely weak electron–photon coupling effect, defect‐free, and highly structural rigidity. The NIR pc‐LED device fabricated by using the optimized Ca3Mg0.97Hf0.97Ge3O12:0.06Cr3+ phosphor combined with blue (λem = 455 nm) LED chip produces an excellent NIR output power of 49.5 mW @ 11.5% under a driving current of 150 mA, which indicates a superiority to the device fabricated by using the well‐known efficient ScBO3:Cr3+ phosphor under the same condition. Therefore, this work not only provides a promising broadband NIR material, but also highlights the design rules for searching high‐performance NIR materials toward spectroscopy applications. [ABSTRACT FROM AUTHOR]

The suspension parameters are vital in the suspension-type abrasive water jet (AWJ) machining of several engineering materials, more so in difficult-to-cut materials, because it significantly influences the suspension stability and sedimentation behaviour of the suspension mixture and abrasive particle acceleration into the AWJs. The suspension stability and abrasive particle acceleration of the suspension-type AWJs are improved by using polymer additives. Hence, it is necessary to study the effect of suspension parameters (abrasive and polymer concentrations) on suspension stability. In this direction, the novel work reported in the paper analyses the stability of suspension by varying the mass percentage of abrasives (garnet and aluminum oxide (Al2O3)) (ωa) and mass percentage of the zycoprint polymer (ωp) in water by considering the Taguchi L9 Orthogonal array (OA). The linear regression (LR) models for the percentage of suspension volume with garnet (VsG) and the percentage of suspension volume with Al2O3 (VsA), are developed. The JAYA algorithm is used to find the optimal combination of the suspension parameters, and its results are in close agreement with the findings from the LR results. The optimum setting of the suspension parameters for both, VsG and VsA, is 3% of ωa and 0.80% of ωp. [ABSTRACT FROM AUTHOR]

Garnet‐type electrolytes show great potential in application of solid‐state lithium batteries due to their high ionic conductivity and wide electrochemical window. However, the formation of surface Li2CO3 derived from air exposure triggers uneven contact with Li‐metal, leading to undesirable dendrite growth and performance deterioration. Herein, the Li3PO4 layer replacing Li2CO3 contaminant is built on garnet surface by taking molten NH4H2PO4 salt driven conversion reaction. The high‐flowability molten salt contributes to conformal formation of Li3PO4, realizing the air‐stable garnet by preventing the re‐attack of H2O/CO2 in air. Besides, the high work of adhesion for Li3PO4 on Li‐metal along with the transformation from Li3PO4 to Li3P/Li2O when contacting with molten Li‐metal enables a lithiophilic interlayer, leading to a seamless Li/garnet contact with ultralow interfacial resistance of 13 Ω cm2. Such ion‐conducting but electron‐insulating layer regulates the uniform distribution of Li‐flux, enabling a large critical current density of 1.2 mA cm−2. Furthermore, the solid LiCoO2/Li cell with the modified garnet delivers a discharge capacity of 130 mAh g−1 at 30 °C, accompanied by a capacity retention of 81% after 150 cycles. This study proposes a promising solution for improvement of air stability and interfacial compatibility of garnet using facile molten salt treatment. [ABSTRACT FROM AUTHOR]

Single-crystalline films (SCFs) of the LuAG: Ce garnet grown using the liquid-phase epitaxy method onto YAG single-crystal (SC) substrates were investigated for possible applications as composite thermoluminescent (TL) detectors. Such detectors may help to register the different components of ionizing radiation fields with various penetration depths, e.g., heavy charged particles and gamma or beta rays. It was found that the TL signal of LuAG: Ce SCF sufficiently differs from that of the YAG substrate concerning both the temperature and wavelength of emissions. Furthermore, even by analyzing TL glow curves, it was possible to distinguish the difference between weakly and deeply penetrating types of radiation. Within a test involving the exposure of detectors with the mixed alpha/beta radiations, the doses of both components were determined with an accuracy of a few percent. [ABSTRACT FROM AUTHOR]

In this study, the infrared optically stimulated luminescence (IRSL) of single crystals of Ce3+ doped yttrium aluminum garnet (YAG) was investigated for the first time. It was found that infrared stimulation of these crystals, following previous exposure to beta radiation, produces a strong luminescence signal. The highest luminescence efficiency was exhibited by the YAG crystal with 0.1% of Ce. With this crystal, it was possible to measure as low doses as 0.1 mGy. Moreover, IRSL is mainly related to the TL peak at a relatively high temperature of c.a. 175 °C, which leads to quite good stability of the signal in time. These properties create good prospects for potential applications of YAG:Ce in dosimetric radiation measurements [ABSTRACT FROM AUTHOR]

The paper addresses the development of composite scintillation materials providing simultaneous real-time monitoring of different types of ionizing radiation (α-, β-particles, γ-rays) in mixed fluxes of particles and quanta. The detectors are based on composite heavy oxide scintillators consisting of a thin single-crystalline film and a bulk single-crystal substrate. The film and substrate respond to certain types of ionizing particles, forming together an all-in-one composite scintillator capable of distinguishing the type of radiation through the different time characteristics of the scintillation response. Here, we report the structure, composition, and scintillation properties under different ionizing radiations of (Lu,Gd,Tb)3(Al,Ga)5O12:Ce films deposited using liquid phase epitaxy onto Gd3(Al1−xGax)5O12:Ce (GAGG:Ce) single-crystal substrates. The most promising compositions with the highest light yields and the largest differences in scintillation decay timing under irradiation with α-, β-particles, and γ-rays were selected. Such detectors are promising for environmental security purposes, medical tomography, and other radiation detection applications. [ABSTRACT FROM AUTHOR]

Garnet-group minerals, with their wide range of compositions, play a significant role in Earth's crust and upper mantle, participating in various petrological and geochemical processes. Oxygen isotope fractionation factors between garnets and other minerals hold crucial implications in these contexts. In this work, vibration frequencies were measured via Raman spectra on five garnet mineral samples in the pyrope-almandine-spessartine ternary system and four synthetic pyrope-grossular solid solutions at temperatures up to 1000 °C and pressures up to 17 GPa. Isobaric (γ iP) and isothermal (γ iT) mode Grüneisen, as well as anharmonic (a i) parameters, were determined for the observed modes. Our study shows that the vibration bands tend to shift to lower frequencies with increasing temperature and to higher frequencies with increasing pressure. Moreover, the anharmonic correction has been found to contribute positively to equilibrium oxygen isotope fractionation β factors in garnets, typically within 0.5 ‰ above 1000 K. The 103∙ln β (T) factors calculated from vibration spectra (considering Г points only) align closely with those from theoretical calculations (including all frequencies in the Brillouin zone). Contributions from phonon dispersion (including none- Г points) are typically smaller than the uncertainties propagated from frequency measurements. Additionally, the pressure effect on the oxygen isotope fractionation in garnet, evaluated from the isothermal Grüneisen parameters, is found to be insignificant under crustal and upper mantle conditions, consistent with thermodynamic expectations. Using published oxygen isotope fractionation β factors for quartz and calcite, the equilibrium oxygen isotope fractionation factors (103∙ln α) are calculated between garnets of diverse compositions and any of these phases as functions of temperature, pressure and fraction of garnet endmembers. Considering composition effects helps to reduce the discrepancies among experimental and empirical calibrations of oxygen isotope fractionation factors between garnet and quartz. As an example application, oxygen isotope fractionation factors 103∙ln α (P , T) between garnets and forsterite were calculated under upper mantle conditions. Our findings suggest that these fractionation factors are predominantly dependent on temperature and garnet compositions, with minor influence from pressure. Compared with our calculated fractionation factors between garnet and olivine, the oxygen isotope exchange equilibrium may have been reached in some in kimberlite and mantle xenolith samples between garnet and olivine. However, in other samples, the fractionation factors cannot be explained solely by the composition effect, likely due to metasomatism. Our results underscore the importance of considering garnet compositions when interpreting their oxygen isotope compositions. • Equilibrium 18O 16O β factors for garnets are derived from vibration frequencies. • The calculated β factors are strongly dependent on temperature and composition. • Pressure effect is marginal on 18O 16O fractionation between garnet and olivine. [ABSTRACT FROM AUTHOR]

In this study we present the results of our density functional theory calculations within the quasi-harmonic approximation, which predict formation and properties of a new compound of the garnet family, La 3 Sc 2 Al 3 O 12 (LSAG). LSAG was shown to be formed from 3LaAlO 3 + Sc 2 O 3 at ambient pressure and room temperature. The thermodynamic stability region of LSAG is limited by a temperature of 685 K, above which its decomposition into LaAlO 3 (LAP) and Sc 2 O 3 occurs. With increasing pressure, LSAG retains its stability up to 0.23 GPa, where the decomposition reaction LSAG ↔ 3LAP＋ Sc 2 O 3 becomes thermodynamically favorable. In this work, not only the thermodynamic stability of LSAG was assessed, but also its thermal conductivity, elastic constants and band gap were calculated. At 300 K the thermal conductivity of LSAG is 13.204 Wm−1K−1. LSAG has the smallest elastic constants compared with YSAG and YAG, which indicates weaker atomic bonding in LSAG than in YSAG and YAG. The width of band gap of LSAG calculated using an hybrid functional is equal to 5.24 eV. In addition, the P–T phase diagram of the known Y 3 Sc 2 Al 3 O 12 (YSAG) was calculated for the first time. Unlike LSAG, YSAG is stable at fairly high temperatures, reaching values of at least 1500 K. With increasing temperature to 1500 K, the pressure of the phase transition increases slightly to 3.55 GPa, and the monovariant curve of the reaction YSAG ↔ 3YAP+Sc 2 O 3 is represented by an almost straight line. [Display omitted] [ABSTRACT FROM AUTHOR]

Broadband near‐infrared (NIR) phosphor‐converted light‐emitting diodes (pc‐LEDs) are recently regarded as the next‐generation smart light sources for miniaturized optical applications. However, their way to practical applications is largely obstructed by the lack of efficient NIR phosphors with photoluminescence (PL) spectrum covering the whole range of 700–1100 nm. Here, an ultra‐broadband NIR phosphor is designed by rationally constructing a Cr3+ → Yb3+ energy transfer system in a garnet crystal Lu2CaMg2Ge3O12 (LCMG). The disordering of the neighboring cations of LCMG is exploited for removing the inversion symmetry of octahedrally coordinated Cr3+ to promote its parity‐forbidden d–d transition probability; meanwhile, efficient Cr3+Yb3+ energy transfer is leveraged not only to enrich the short‐wave NIR PL in 950–1100 nm, but also to greatly improve the internal quantum efficiency (QE) (from 57.8% to 84.2%) as well as thermal stability. The resulting high external QE (35.6%) enables the demonstration of ultra‐broadband NIR pc‐LED with a record NIR output power of 93.2 mW (350 mA), which promises better performance of pc‐LEDs in non‐visible optical applications. This work provides a possible paradigm for developing ultra‐broadband NIR phosphors activated by transition metal ions. [ABSTRACT FROM AUTHOR]

High‐quality laser‐driven lightings require not only high luminous flux (LF) but also uniform spectral distribution. Herein, the green‐emitting Lu3Al5O12:Ce3+ (LuAG:Ce) and red‐emitting CaAlSiN3:Eu2+ (CASN:Eu) commercial phosphor powders with high‐performance are fabricated into phosphor‐in‐glass film (PiGF) sintered on sapphire plate, and further served as a motor‐driven rotatory "phosphor wheel" to receive pumping of blue laser in a reflective excitation light path. The greatly relieved thermal pressure, benefited from the high‐thermal‐conductivity sapphire substrate and the pulse‐like rotatory excitation mode, efficiently retards the occurrence of luminescence saturation. Remarkably, the photon reabsorption phenomenon in the conventional "phosphor mixture" design is well solved by introducing a smart "phosphor pattern" design, free of causing inhomogeneous angular color distribution at the same time. The constructed LuAG:Ce PiGF‐based lighting source yields high brightness of 2970 lm@21 W mm−2, and the constructed LuAG:Ce PiGF‐CASN:Eu PiGF‐based lighting source yields luminosity‐chromaticity balanced white light with LF higher than 1000 lm and color rendering index of 80–90. [ABSTRACT FROM AUTHOR]

The nanocrystalline single‐phase Er3+‐doped Yb3Ga5O12 garnets have been prepared by the sol‐gel combustion technique with a crystallite size of ≈30 nm. The presence of Yb3+ in garnet hosts allows their efficient excitation at the ≈977 nm wavelength. The Er3+ doping of Yb3Ga5O12 garnet host results in deep red Er3+: 4F9/2 → 4I15/2 upconversion photoluminescence (UCPL) emission. The dominance of the red UCPL emission over the green Er3+: 4F7/2/2H11/2/4S3/2 → 4I15/2 component was investigated using the measurement of the steady‐state and time‐dependent Er3+ and Yb3+ emission spectra in combination with the power‐dependent UCPL emission intensity. The proposed upconversion mechanism is discussed in terms of the Er3+ → Yb3+ energy back transfer process as well as Yb3+(Er3+) → Er3+ energy transfer and Er3+ ↔ Er3+ cross‐relaxation processes. The studied Er3+‐doped Yb3Ga5O12 garnet may be utilized as a red upconversion emitting phosphor. [ABSTRACT FROM AUTHOR]

Powders of single-phase solid solutions based on cerium-doped gadolinium-scandium-aluminum garnet were synthesized by coprecipitation from aqueous solutions followed by annealing at 1600 °C. The solubility limit of cerium in gadolinium-scandium-aluminum garnet was determined by X-ray powder diffraction and scanning electron microscopy. It has been demonstrated that the solubility limit of cerium depends not only on the concentration of scandium in the solid solution but also on the fraction of Sc3+ cations in the dodecahedral and octahedral positions of the garnet crystal lattice. Based on the X-ray luminescence spectra of Ce3+ (∼575 nm, 5d→4f transition) in single-phase samples, the composition (Gd 2.73 Ce 0.02 Sc 0.5 Al 4.75 O 12) with the highest X-ray luminescence was determined. A diamond composite "Diamond-GSAG:Ce" with Gd 2.73 Ce 0.02 Sc 0.5 Al 4.75 O 12 particles has been fabricated, which exhibits intense yellow X-ray luminescence, that is visible to the eye. The investigated class of composites is promising for applications in stable detectors and visualizers of high-intensity X-ray radiation in synchrotrons and free-electron lasers. [ABSTRACT FROM AUTHOR]

GYGAG(Ce) transparent ceramic garnet scintillators were irradiated with electrons from 0.5 to 2 MeV with fluences from $10^{16}\,\,\text{e}^{-}$ /cm2 to $10^{19}\,\,\text{e}^{-}$ /cm2, corresponding to doses from 0.3 to 310 Gigarad. Absorption spectra were measured before and after irradiations. Light yields from alpha, beta, and gamma excitations were measured before and after irradiation and compared to preirradiation values to gain a deeper understanding of how electron irradiations can affect light yield, as well as defects generated in both the surface and bulk. Within experimental error, no degradation in light yield was observed for the electron-irradiated samples, as measured via beta or gamma excitation, with minimal degradation observed via alpha excitation. A small increase in optical absorption near the wavelength of emission was observed following the largest dose irradiation. These results suggest that GYGAG(Ce) is radiation hard to electron irradiation up to $10^{19}\,\,\text{e}^{-}$ /cm2 and doses up to 310 Gigarad. This robustness to irradiation indicates that transparent ceramic garnets may prove useful for applications such as scintillation-based nuclear batteries by allowing for higher energy beta emitters, increased power densities, and enabling long service lifetimes. [ABSTRACT FROM AUTHOR]

In the dual‐emitting Eu3+‐activated Sr2NaMg2V3O12 garnet, vibrationally induced thermometric response and thermochromic luminescence are investigated for the first time. Based on the diverse thermal quenching of VO43− and Eu3+ along with the advantage of variation in the fluorescence intensity ratio, a potential phosphor for sensitive dual‐mode ratiometric and colorimetric temperature sensors is proposed in which maximum absolute and relative sensitivity of 0.0135 K−1 and 1.61% K−1 are obtained at 420 K with a temperature resolution

In recent years the topic of frustrated magnetism has attracted significant scientific interest that shows little sign of abating. Within the field of frustrated magnetism, the compound Gd3Ga5O12 was, for many years, the archetypal frustrated magnet with a ground state that could not be elucidated. Recently an unusual emergent ground state, a director state, has been determined for Gd3Ga5O12, which is now also observed for other isostructural compounds. In this review an overview of the director state is given, starting with the basics of rare earth magnetism and leading to a summary of the experimental signatures that led to the insight needed to determine the director state.

Two novel garnet-type ceramics Ca3MZrGe3O12 (M = Co and Zn) with pure phase were prepared through a solid-state reaction method. Structure–property relationships were studied by the Rietveld refinement and Raman spectra. The appearance of two weak symmetric stretching vibrational peaks in Ca3ZnZrGe3O12 might be due to the lower ordering. Higher Q × f value in Co-analogue was related to the larger packing fraction and the lower FWHM of A1g mode. The smaller oxygen bond valence in Ca3CoZrGe3O12 indicates a smaller τf value. At the optimized sintering temperature of 1280 °C, Ca3CoZrGe3O12 shows desirable microwave dielectric properties with εr of 10.37, Q × f value of 60,100 GHz, and τf value of −28.5 ppm/oC. The Ca3ZnZrGe3O12 ceramic sintered at 1200 °C has the best microwave dielectric properties with εr of 10.48, Q × f value of 49,700 GHz, and τf value of −35.8 ppm/oC.

Recent decades have shown arising growth-on-demand fusion of machine learning into all of the areas of chemistry and materials science. In this study, we examine one aspect of using these technologies to gain an advantage in the search for new knowledge in increased amounts of experimental data. The novelty detection approaches are aimed to identify the data artefacts. The analysis of such artefacts, "outliers", in details of synthesis of garnet-structured solid electrolytes was chosen as an example of the practical application of this methodology. Particular attention was paid to the choice of the precursors. The thermodynamic data such as the heat of formation from the pure oxides as well as the results of drop solution calorimetry for simple oxides were involved as the descriptors for the studied systems. The overall performance of novelty/outlier detection of "outliers" was characterized using the AUC (area under the curve) value and assessed to be 0.71 – 0.72 varying the complexity of data description. It was found that all "outlier" due to the precursors choice compounds were successfully identified. The regression analysis was performed to analyze the impact of outlier/novelty detection on model predictive performance as well as to elucidate the relationship with the data diversity and the complexity of data description. The novelty detection approaches are aimed to identify the data artefacts. The analysis of such artefacts, "outliers", in details of synthesis of garnet-structured solid electrolytes was performed. • A novelty detection is aimed at identifying the artefacts in the analyzed data. • The details of synthesis for garnet-structured solid electrolytes were analyzed. • Particular attention was given to the choice of the precursors. • The problem of the complexity of data description was considered. [ABSTRACT FROM AUTHOR]

We report systematic first-principles results of structural properties and compression behavior based on density functional theory (DFT) and an exchange-correlation functional for solids, of Al-bearing garnets of general compositions in the pyrope-almandine-grossular solid solution system. The combination of DFT and a simple solid solution model is able to produce a compositional dependence of the compression curve consistent with trends observed in experimental studies. Using end-member properties extrapolated from our computations and perturbing an extant thermodynamic model we observe only marginal effects on the bulk sound velocity of pyrolite and MORB along relevant geothermal paths. However, this could hide important effects on the elemental partitioning between garnet and other major phases which should be further investigated both experimentally and computationally. We also present simulations of the effect of combined Fe and Ca substitutions for Mg on the elastic tensor of Al-bearing garnets, our simplified modeling shows only partial agreement with the trends observed in experiments. Therefore, further computational investigations, especially of the effect of Fe-Mg substitution on the tensor, are needed. [Display omitted] [ABSTRACT FROM AUTHOR]

Mn3Al2Ge3O12 is a member of the garnet family of compounds, A3B2(CO4)3, whose magnetic properties are affected by a high degree of geometrical frustration. The magnetic frustration is at the origin of the intriguing magnetic properties that these materials exhibit, such as a long range hidden order derived from multipoles formed from 10-spin loops in the gadolinium gallium garnet, Gd3Ga5O12. Mn3Al2Ge3O12 garnet is isostructural to the thoroughly investigated Gd garnets, Gd3Ga5O12 and Gd3Al5O12. Moreover, in Mn3Al2Ge3O12, the Heisenberg-like Mn2+ magnetic ions (L= 0) are also arranged in corner sharing triangles that form a hyperkagomé structure. The identical crystallographic structures and similar Heisenberg-like behaviour of the magnetic ions make manganese aluminium germanium garnet the closest compound to the gadolinium garnets in its magnetic properties. Here, we report, for the first time, the growth of a large, high quality single crystal of the Mn3Al2Ge3O12 garnet by the floating zone method. X-ray diffraction techniques were used to characterise and confirm the high crystalline quality of the Mn3Al2Ge3O12 crystal boule. Temperature-dependent magnetic susceptibility measurements reveal an antiferromagnetic ordering of the Mn2+ ions below TN= 6.5 K. The high quality of the single crystal obtained makes it ideal for detailed investigations of the magnetic properties of the system, especially using neutron scattering techniques.