Effect of calcination temperature on B-site vacancy content of La0.75Sr0.25Mn0.92Δ0.08O3− perovskite
| Autor: | Denghui Ji, Xinju Xiao, Liwei Wang, Congmin Zhang, Zhi-wei Zeng, Shuling Wang, Xing-ze Ge |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Analytical chemistry 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology 01 natural sciences law.invention Crystal Magnetization chemistry.chemical_compound Crystallography Lanthanum manganite chemistry Geochemistry and Petrology law Vacancy defect 0103 physical sciences Curie temperature Calcination 0210 nano-technology Powder diffraction Perovskite (structure) |
| Zdroj: | Journal of Rare Earths. 36:287-297 |
| ISSN: | 1002-0721 |
| DOI: | 10.1016/j.jre.2017.05.014 |
| Popis: | Lanthanum manganite with cation vacancies from nominal La0.75Sr0.25Mn0.92Δ0.08O3−δ nanocrystalline powder was successfully prepared at different calcination temperatures using the sol–gel method. X-ray diffraction shows that as the calcination temperature (TCal) 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 TCal = 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 Mn3+ and Mn4+ cations. A core–shell model is proposed for vacancies located on the surfaces of the crystal particles. As an application, the magnetic moment angle θij between Mn3+ and Mn4+ cations on the surface, which decreases with decreasing vacancy content, can be obtained. |
| Databáze: | OpenAIRE |
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