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With high‐temperature solid‐state reaction method, a series of Lu2Sr(1−x)Al4SiO12:xEu2+ phosphors have been synthesized. With Rietveld refinement method, the crystal structure of Lu2SrAl4SiO12 has been refined. Under the excitation of the ultraviolet and violet band light, Lu2Sr(1−x)Al4SiO12:xEu2+ emits the Eu2+ characteristic blue broadband light. The photoluminescence properties of concentration quenching, emission peak shift, reflectance spectra, and luminescence decay have been investigated. With the structure analyses, the corresponding physical mechanisms have been discussed. With the increased temperature, this phosphor shows well thermal stabilities. For the xEu = 0.06, 0.08, and 0.1 phosphors, the strong anti‐thermal quenching performance has been observed. The reason for the anti‐thermal quenching of this phosphor has been discussed. The trap capture mechanism may be the suitable physical mechanism to explain the anti‐thermal quenching of this phosphor. This phosphor shows the potential applications in the white LED lighting fields. [ABSTRACT FROM AUTHOR]

Synchrotron X-ray powder diffraction data are analyzed in detail by the Rietveld structure refinement program to obtain microscopic structure changes of Sr0.5Ba0.5Nb2O6 (SBN50) doped with combinations of Ce and Cr. The defects of Ce and (Ce,Cr)-doped SBN50 are determined by the densification behavior, and it is found that creation of Nb vacancies and self-compensation are the defect reactions for Ce and (Ce, Cr) dopants, respectively. The variations of the lattice parameters of a and c axes with doping content are determined by the changes of the distance between A1 and A2 sites via Coulomb interactions and the mean bond length of Nb(1)–O(4), respectively. It is confirmed that the polarization of SBN50 is mainly determined by the displacement of Nb ions. The effect of random fields induced by the impurities of the combinations of Ce and Cr on the displacement of off-center Nb ions has been reasonably explained. [ABSTRACT FROM AUTHOR]

The electronic conduction behavior above the Verwey-like transition temperature ( Tv) of Ni2+- and Al3+-doped LiMn2O4 has been reassessed. The nonadiabatic small-polaron model is adopted to assess the conduction mechanism. The Jahn–Teller distortion and short-range ordering are found to play a role in the variations of the lattice parameter and conduction behavior above Tv. It is also found that the effect of the dopant content on the activation energy is minor but is significant on the preexponential factor during the hopping process above Tv. In simultaneously comparing the effects of the dopants with quite different chemistry on the electronic-conduction behavior in Ni2+- and Al3+-doped LiMn2O4, it indeed provides a deep sight into understanding the fundamental conduction mechanism above Tv. [ABSTRACT FROM AUTHOR]

Undoped and La-doped Bi2Fe4O9 ceramics were synthesized using a soft chemical method. It is observed that in calcining La-doped Bi2Fe4O9, Bi(La)FeO3 phase rather than Bi2− xLa xFe4O9 gradually increases with increasing La doping content. The phase conversion from mullite-type structure of Bi2Fe4O9 to rhombohedrally distorted perovskite one of Bi(La)FeO3 with increasing La doping content indicates that La doping can stabilize the structure of BiFeO3. This is further evidenced that Bi2Fe4O9 can be directly converted to Bi(La)FeO3 by heating the mixtures of nominal composition of Bi2Fe4O9/ xLa2O3. Furthermore, the microstructure changes and the room temperature hysteresis loops and leakage current for Bi2− xLa xFe4O9 with x=0 and 0.02 were characterized. [ABSTRACT FROM AUTHOR]