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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]

[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).

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.

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]

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]

The development of innovative high-power lighting sources is urgently required to design and investigate the new high structural quality and high-temperature stable converters in the form of single crystals and single crystalline films. This research deals with the growth and investigation of structural, luminescence, and photoconversion properties (color coordinates, color temperature and color rendering index) of the single crystalline films of Ce3+ doped (Lu, Y, Tb, Gd) 3 Al 5 O 12 garnets, grown using the Liquid Phase Epitaxy method onto undoped Y 3 Al 5 O 12 substrates. The combination of Ce3+ doped Lu 3 Al 5 O 12 , Y 3 Al 5 O 12 , Tb 3 Al 5 O 12 , Gd 2.9 Lu 0.1 Al 5 O 12 film converter with respective thickness with commercial blue LED allows for obtaining green-yellow-orange-emitting pc-WLEDs. The application of the mentioned film converters results in the formation of four basic trends on the color diagram depending on the thickness of the converter. • TThe study addresses the urgent demand for high-power lighting by investigating single crystalline film converters with superior structural and thermal properties. • The LPE technique is employed to grow garnet films on undoped YAG substrates. • The research analyzes the structural, luminescent, and photoconversion properties of (Lu, Y, Tb, Gd)AG:Ce films. • By combining converters and blue LEDs, the study successfully produces pc-WLEDs with green, yellow, and orange tints. • By varying converter thickness, the researchers reveal four distinct color trends on the diagram. [ABSTRACT FROM AUTHOR]

High-entropy garnet crystal structure compounds with novel chemical compositions (Y 3-x-y-z Ca x Li y Ln z Ga 5-m Al m O 12) (Ln – Ce, Eu, Tb) have been synthesized by an aqueous sol-gel method. The multinary substitution of yttrium by calcium, lithium and lanthanide element (cerium, europium and terbium) effects in these gallium/aluminium garnets have been investigated. The intermediates and synthesized end products were characterized by thermal analysis (TG/DTG/DSC), powder X-ray diffraction analysis (XRD), FT-IR spectroscopy and scanning electron microscopy (SEM). The different effects of multinary substitution with calcium, lithium and lanthanide ions in Y 3-x-y-z Ca x Li y Ln z Ga 5-m Al m O 12 samples in comparison with single-metal substitution cases were determined from the results of XRD analysis. The XRD patterns of these samples clearly showed that single phase cubic structure garnets have been synthesized at low substitutional level of yttrium by calcium, lithium and lanthanide element (cerium, europium and terbium). The luminescent properties of (Y 3-x-y-z Ca x Li y Ln z Ga 5-m Al m O 12) (Ln – Ce, Eu, Tb) garnets were also investigated. • Substituted (Y 3-x-y-z Ca x Li y Ln z Ga 5-m Al m O 12) garnets have been synthesized by sol-gel method. • The substitution effect of the Ce, Eu, Tb lanthanides in mixed-metal garnets was investigated. • The substitutional level depends very much on the nature and amount of introduced elements. • Different effects of multinary substitution with calcium, lithium and lanthanides were observed. • The luminescent properties of novel garnets were also investigated. [ABSTRACT FROM AUTHOR]

Thin films of ferrimagnetic iron garnets can exhibit useful magnetic properties, including perpendicular magnetic anisotropy (PMA) and high domain wall velocities. In particular, bismuth-substituted yttrium iron garnet (BiYIG) films grown on garnet substrates have a low Gilbert damping but zero Dzyaloshinskii-Moriya interaction (DMI), whereas thulium iron garnet (TmIG) films have higher damping but a nonzero DMI. We report the damping and DMI of thulium-substituted BiYIG (BiYTmIG) and TmIG|BiYIG bilayer thin films deposited on (111) substituted gadolinium gallium garnet and neodymium gallium garnet (NGG) substrates. The films are epitaxial and exhibit PMA. BiYIG|TmIG bilayers have a damping value that is an order of magnitude lower than that of TmIG, and BiYIG|TmIG|NGG have DMI of 0.0145 ± 0.0011 mJ/m 2 , similar to that of TmIG|NGG. The bilayer therefore provides a combination of DMI and moderate damping, useful for the development of high-speed spin orbit torque-driven devices.

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., (© 2024 John Wiley & Sons Ltd.)