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Inorganic chiral materials have attracted increasing attention due to their application prospects. In this work, we synthesized the chiral nanostructured bismuth oxychloride co‐doped with Er3+/Yb3+ phosphor (D‐BYEP) by hydrothermal growth with a subsequent air‐annealing strategy using chiral sugar alcohols as the chiral inducer. The D‐BYEP emitted bright red light under the excitation of 980 nm near‐infrared laser. The temperature sensing behavior was evaluated by employing the thermally coupled (TCLs) or non‐thermally coupled (NTCLs) levels of Er3+. The maximum relative sensitivities (SR) obtained are 0.84% K−1 and 1.30% K−1 (298 K), respectively. The results show that the D‐BYEP may be ideal candidates for optical temperature sensors. We anticipate that this new type of inorganic chiral phosphor may have a range of applications in temperature measurement of light sources. [ABSTRACT FROM AUTHOR]

Photochromic reaction-induced reversible luminescence materials have attracted extensive attention and research in information storage, anticounterfeiting and other aspects. The reversible luminescence regulation could induced photochromic reaction by external fields stimulation. However, most of the bleaching methods stay in the high temperature thermal stimulation bleaching, which has low efficiency and long reaction time, thus limiting its application. In this work, the CaWO4: Yb3+, Ho3+, Bi3+ ceramics were prepared to realize the reversible regulation of photoluminescent and photochromism by light stimulation. The CaWO4: Yb3+, Ho3+, Bi3+ ceramics turn gray after being exposed to 254 nm ultraviolet light for 25 min, and then turn white under the irradiation of 532 nm laser for 10 s to restore to the original state. The cation vacancies and oxygen vacancies formed in co-doped Bi3+ CaWO4 ceramics lead to photochromic effect. CaWO4: Yb3+, Ho3+, Bi3+ ceramics realize reversible dual mode upconversion and downconversion luminescence, improving security and reliability in anticounterfeiting. The reversibility photoluminescent and photochromism of CaWO4: Yb3+, Ho3+, Bi3+ ceramics was verified by 245-nm ultraviolet coloration and 532-nm laser bleaching, which indicates that CaWO4: Yb3+, Ho3+, Bi3+ ceramics have potential application prospects as anticounterfeiting agents. [ABSTRACT FROM AUTHOR]

Electronic components made by inorganics (e.g., mica) play key roles in the function exertion of instruments working in outer‐layer space, enduring long‐term β‐ray irradiation. Its damage is vital while explored rarely. Herein, pure muscovite crystals were chosen and irradiated by an electron beam (EB) in air with a dose up to 1000 kGy. Then, micro‐geometry morphology variation in Z‐axis and microstructural transformation mechanism were explored by X‐ray diffraction, Fourier transform attenuated total reflection infrared spectrum, thermogravimetric analysis, X‐ray photoelectron spectroscopy, and CA analysis. Main results reveal that muscovite lattice is unstable to EB irradiation. With dose increases to 1000 kGy, interlayer space d of (0 0 2) lattice varied 2% near 0.2 Å. At low‐dose, irradiation lattice expansion readily occurs, whereas at higher dose, it is lattice shrinkage, showing a transformation from expansion to shrinkage. Concurrently, chemical structure varied, H2O amount increased, and metal element valance and surface wettability were reduced, so dehydroxylation occurred exceeding H2O radiolysis and evaporation, and framework cleavage could be severe. Binding energies of metals of 1000 kGy‐irradiated species decreased by 0.2 eV, and CA of 100 kGy‐irradiated species increased by 10°. Intrinsic mechanisms involve framework destruction, H‐atom migration, hydrogen bond formation/destruction, and H2O radiolysis. At low‐dose irradiation, H‐atom migration and hydrogen bond formation/destruction are predominant, inducing lattice expansion; at higher dose, framework cleavage is intensive and crucial, inducing shrinkage. During which, partial H2O occurred radiolysis, reducing valence. Generally, H‐atom migration and interface cleavage played key roles in microgeometry morphology a variation of muscovite crystal under EB irradiation at 0–1000 kGy. To enhance muscovite geometry‐morphology stability under a long‐term β‐ray irradiation condition, OH and hydrogen bond contents should be reduced and interface region should be strengthened (e.g., lessening vacancies or compacting stacking). This conclusion promotes the design of radiation‐resistant silicate material, guiding the manufacturing of electronic component used in aerospace industry significantly. [ABSTRACT FROM AUTHOR]

The materials showing significant photostrictive effect under visible light are of great interest for the development of advanced micro‐optomechanical systems (MOMS). Till date, ferroelectrics have remained the most widely investigated materials for photostriction, but due to wide bandgap their efficiency remains poor in visible light. Herein, magnesium orthovandate (Mg3V2O8) ceramics, showing a bandgap of 2.43 eV, is demonstrated for significant photostrictive efficiency (η) under visible light. In the illumination of laser 655 nm, it shows η = 1.5 × 10−11 m3/W, the highest efficiency ever reported for any ceramic under visible light, and under laser405 nm, shows η = 1.0 × 10−11 m3/W, the efficiency higher than most of the reported materials in similar illumination conditions. The in situ X‐ray diffraction patterns collected under external laser illumination in conjunction with power dependent Raman spectroscopy indicates that the photostriction of Mg3V2O8 ceramics is attributed to light induced distortion of its VO4 tetrahedrons and MgO6 octahedrons. Whilst, comparative analysis of Raman modes identified experimentally and modes calculated by density functional theory reveals that the light‐triggered electron–phonon resonating interactions and light‐induced phase transition are the most likely origin of large polyhedral distortions and hence higher value of η at specific light intensity of lasers 655 and 405 nm, respectively. These results show considerable advantage of Mg3V2O8 ceramics for MOMS and other light‐driven applications. [ABSTRACT FROM AUTHOR]

The bulk photovoltaic effect in ferroelectric materials exhibits great potential in photoelectric applications. However, their photoresponse is generally limited to the UV region due to the wide bandgap feature of most perovskite ferroelectric materials, while the narrowing of bandgap is often accompanied by the degradation or even extinction of the ferroelectric polarization. Herein, 0.5Ba(Zr0.2Ti0.8)O3‐0.5(Ba0.7Ca0.3)TiO3 (BZT‐BCT) with bandgap of 2.4 eV arising from the existence of Ti3+ is prepared, and then titanium vacancies are introduced to BZT‐BCT ferroelectric solid solutions through B‐site off‐stoichiometry (0.5Ba(Zr0.2Ti0.8)O3‐0.5(Ba0.7Ca0.3)Ti1 −x%O3, BZT‐BCT1 −x%) to further tune the bandgap. Lowest bandgap of 2.1 eV with near‐infrared (NIR) absorption is obtained for BZT‐BCT0.990 composition. Moreover, both the ferroelectricity and piezoelectricity (Pr = 14.3 μC/cm2, d33 = 415 pC/N) are well maintained after mitigating the effect of the increased oxygen vacancies associated with Ti‐deficiency on the spontaneous polarization by oxygen‐annealing treatment. More specifically, the oxygen‐annealing BZT‐BCT0.985 composition, showing at least 2.4‐fold photovoltage and 2.2‐fold photocurrent of the pristine BZT‐BCT ceramic, exhibits excellent transient pyroelectric current and stable photovoltaic current under xenon, NIR, and monochromatic visible lights. The photoelectric device based on the oxygen‐annealing BZT‐BCT0.985 ceramic performs wide‐spectrum photodetection properties from 405 nm light to NIR light, which makes it a potential candidate for self‐powered photodetector applications. [ABSTRACT FROM AUTHOR]

Photostrictive effect that has been discovered for over half a century is getting renewed interest in recent years in view of the great potential for the wireless remote‐control technology. Compared with lead lanthanum zirconate titanate (PLZT) ferroelectrics that have been intensively studied, Bi0.5Na0.5TiO3 (BNT) ceramics have a more environment‐friendly prospect. In this study, we present a significant photostrictive response for Bi0.5Na0.5TiO3 ceramics under visible light illumination. The ultraviolet–visible diffuse reflectance spectrum indicates that the BNT ceramic is a direct bandgap semiconductor (Eg = 2.93 eV) with a long tail absorbance till wavelength ~560 nm. Transmission electron microscopy analysis reveals nanoscale domains and fluctuated local structure in BNT ceramics. A significant photostriction ΔL/L about 0.08% was observed for BNT when irradiated by 405‐nm laser at the power of 20 kW/m2. The nonuniform shifts of the X‐ray diffraction peaks under external laser illumination indicates that the photostriction is mainly attributed to the light‐induced distortion of crystalline lattice. Such a big deformation approaching that of piezoelectrics/ferroelectrics induced by electric field shows great promise for photo‐driven multifunctional applications. [ABSTRACT FROM AUTHOR]