The Structural, Magnetic, and Magnetocaloric Properties of La1−xAgxMnO3 (0.05 ≤ x ≤ 0.25)

• Published in: Journal of superconductivity and novel magnetism Vol. 29; no. 8; pp. 2075 - 2084
• Main Authors: Coşkun, A., Taşarkuyu, E., Irmak, A. E., Aktürk, S., Ekicibil, A.
• Format: Journal Article
• Language: English
• Published: New York Springer US 2016
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Magnetic Materials; Magnetism; Original Paper; Physics; Physics and Astronomy; Strongly Correlated Systems; Superconductivity; Magnetic entropy change; Manganite; Sol-gel; Curie temperature
• ISSN: 1557-1939; 1557-1947
• DOI: 10.1007/s10948-016-3516-0

We have investigated structural, magnetic, and magnetocaloric properties of monovalent Ag-doped La 1− x Ag x MnO 3 (0.05 ≤ x ≤ 0.25) compounds. The materials were prepared by the sol–gel method and then characterized by X-ray diffraction (XRD). The XRD results indicated that all the samples have a single phase of hexagonal (rhombohedral) structure with the R 3 ¯ c space group. The morphology and particle size distributions were investigated using scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS). The SEM images showed that the grain sizes are smaller than 1 μ m and remain the same with increasing Ag concentrations. The magnetic properties were studied by measuring magnetization and varying temperature ( M ( T )) and external magnetic field ( M ( H )). The M ( T ) measurements show that with decreasing temperature all samples exhibit a paramagnetic-to-ferromagnetic phase transition. The Curie temperature, T C , increases from 200 to 290 K as Ag doping increases from 0.05 to 0.25. The magnetic entropy change (|− SM |) is obtained in all samples near the Curie temperatures at a magnetic field change of 3 T. Furthermore, their maximum relative cooling power (RCP) values were found to be 82.492, 82.614, and 127.375 J/kg for x = 0.10, 0.15, and 0.25.