Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1623237 | Journal of Alloys and Compounds | 2009 | 5 Pages |
Abstract
The nominal compositions of La1.4Sr1.6âxCaxMn2O7 (0.0 â¤Â x â¤Â 1.6) have been synthesized using solid-state reaction method. The XRD analyses show that the compounds are pure I4/mmm tetragonal bilayered perovskites phase for x â¤Â 0.8, while they are mixture of a main orthorhombic ABO3-type perovskite and a slight cubic calcium oxide for x â¥Â 1.0. For lightly doped samples (x â¤Â 0.8), the 3D ferromagnetic (FM) transition temperature first declines and then disappears due to the depression of the interlayer exchange interaction by Ca2+ doping. However, the intralayer exchange interaction is strengthened in the x = 0.4 sample on account of large Jahn-Teller distortion of MnO6 octahedra. A large magnetic entropy change of 2.28 J kgâ1 Kâ1 is obtained in the nominal composition La1.4Sr1.6âxCaxMn2O7 (x = 1.6) upon 1 T applied magnetic field, which makes it suitable for sub-room temperature magnetic cooling material.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
X. Zhao, W. Chen, Y. Zong, S.L. Diao, X.J. Yan, M.G. Zhu,