| 2 | Effect of calcination temperature on B-site vacancy content of La0.75Sr0.25Mn0.92△0.08O3-δperovskite显示文摘Lanthanum manganite with cation vacancies from nominal La_(0.75)Sr_(0.25)Mn_(0.92)△_(0.08)O_(3-δ) nanocrystalline powder was successfully prepared at different calcination temperatures using the sol-gel method. X-ray diffraction shows that as the calcination temperature(T_(Cal)) increases, the crystal particle diameter increases, but the B-site vacancy content decreases. According to a powder diffraction profile fitting technique and transmission electron microscopy results, the vacancy content can be estimated as 0.08,0.01, and 0.005 for T_(Cal) = 1073,1273, and 1473 K, respectively. Magnetization versus temperature curves show that the magnetic transition temperatures, including the Curie temperature, are influenced by both B-site vacancies and double-exchange interaction between Mn^(3+) and Mn^(4+) cations. A core-shell model is proposed for vacancies located on the surfaces of the crystal particles. As an application, the magnetic moment angle θ_(ij) between Mn^(3+) and Mn^(4+) cations on the surface, which decreases with decreasing vacancy content, can be obtained. | Denghui Ji Shuling Wang Xingze Ge Xinju Xiao Liwei Wang Zhiwei Zeng Congmin Zhang | 2018 | Journal of Rare Earths2018，36，3： | 0 |
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