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Effect of A-site ionic disorder on the structure, magnetic, and magnetocaloric properties of La0.7−xNdxCa0.3−y(Ba,Sr)yMnO3.
- Source :
-
Journal of Applied Physics . 2/7/2020, Vol. 127 Issue 5, p1-11. 11p. 4 Charts, 11 Graphs. - Publication Year :
- 2020
-
Abstract
- The effects of A-site cation size mismatch on La0.7 − xNdxCa0.3 − y(Ba,Sr)yMnO3 perovskite materials with a constant A-site average ionic radius ⟨rA⟩ = 1.2052 Å have been investigated. Polycrystalline samples have been prepared through the standard solid-state reaction method at high temperatures, and their structures, magnetic properties, and magnetocaloric effect (MCE) have been investigated in detail. X-ray diffraction patterns show that all of the samples crystallized in an orthorhombic structure with the space group Pnma. XPS analysis confirmed the Mn3+/Mn4+ ratio remained constant as σ2 was varied. Meanwhile, upon increasing σ2 from 0.0002 to 0.007, the Curie temperature (TC) decreased linearly from 254 K to 108 K. Based on M-H isotherms, Arrott plots and the maximum magnetic entropy prove a crossover of first-to-second-order transition with increasing σ2. Samples with σ2 = 0.0002, 0.001, and 0.003 exhibited a first-order transition and had larger MCEs than those showing a second-order transition. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00218979
- Volume :
- 127
- Issue :
- 5
- Database :
- Academic Search Index
- Journal :
- Journal of Applied Physics
- Publication Type :
- Academic Journal
- Accession number :
- 141626397
- Full Text :
- https://doi.org/10.1063/1.5120740