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Dielectric and photoluminescence properties of fine-grained BaTiO <sub/>3</sub> ceramics co-doped with amphoteric Sm and valence-variable Cr
摘要: Dielectric and photoluminescence properties of fine-grained BaTiO3 ceramics co-doped with amphoteric Sm and valence-variable Cr (Ba1-xSmx)(Ti1-xCrx)O3 (BSTC) and (Ba1-xSmx)(Ti1-(x-0.01)Crx-0.01)O3 (BSTC1) ceramics with a single-phase perovskite structure were prepared using a traditional solid state based method. The structure, microstructure, site occupations, valence states of Cr, photoluminescence, and dielectric properties of these ceramics were investigated using XRD, SEM, EDXS, RS, EPR, XPS, and dielectric measurements. All ceramics exhibit a fine-grained microstructure (0.7 mm). Three valence states of Cr ions were confirmed and Cr predominates as Cr3+ enter the Ti4+ sites with a stronger EPR signal (1.974). The RS bands of high-wavenumber were attributed to photoluminescence from Sm3+ ions. The formation of SmBa?-CrTi' defect complexes play leading roles in the removal of VO??, prevent the grain growth, and photoluminescence quenching. (Ba1-xSmx)(Ti1-(x-0.01)Crx-0.01)O3 (BSTC1) ceramics with amphoteric Sm3+ ions exhibit a regular diffuse phase transition behavior, rapid Tm-shifting rate of -24.3 °C/at% (Sm/Cr), higher εRT; lower tan δ and x = 0.04 and 0.05 met the EIA Y5V specification.
关键词: Sm and Cr doping,BaTiO3 ceramics,photoluminescence,dielectric properties,co-doping
更新于2025-09-19 17:15:36
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Meso-kinetics of one time relaxation electrical processes in BaTiO <sub/>3</sub> ceramics—modified Boltzmann-Poisson model
摘要: This paper is focused on the research an improved version of the Boltzmann-Poisson model for BaTiO3-ceramics. In the approximation of one relaxation time, for constant external electrical field, this approach included correct quadratic relation for varistor effect in the case of the Heywang model. Within meso-kinetics, quantum corrected Boltzmann-Poisson model, contains space-time correlations for the probability distribution density function f(r, k, t), fractional relaxation velocity description. These new results corresponds to our other research based on electronic particles Brownian motion within its fractal nature.
关键词: Brownian motion,BaTiO3-ceramics,fractals,Heywang model,Boltzmann-Poisson model,dielectrics
更新于2025-09-10 09:29:36