Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1606379 | Journal of Alloys and Compounds | 2016 | 7 Pages |
Abstract
In this work, the structural, electrical, magnetic and magneto-caloric properties of the La0.70Ca0.21Ag0.09MnO3 compound were investigated. The compound was prepared by the sol gel method and sintered at 1000 °C for 24 h. Powder X-ray diffraction pattern (XRD) analyzes reveals a single phase orthorhombic structure with the Pnma space group as shown by the Rietveld analysis. The grainy morphology was confirmed with a grain size variation of 0.5-1.5 μm by using scanning electron microscopy (SEM) and atomic force microscopy (AFM) images. High resolution transmission electron microscopy (HR-TEM) results strongly support an orthorhombic structure with the parameters calculated from the XRD data. Ferromagnetic-paramagnetic phase transitions occur at â¼263 K (Curie temperature, TC) and â¼265 K (metal-insulator, TMI). The sample undergoes a sharp metal-insulator transition at TMI following the sharp paramagnetic-ferromagnetic transition TC. From the isothermal magnetization measurements (MâH), the maximum magnetic entropy change |ÎSM| was calculated to be â¼4.8 J/kgK for an applied field change of 1 T, which is greater than that of pure Gd.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
A. CoÅkun, E. TaÅarkuyu, A.E. Irmak, S. Aktürk,