Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9803902 | Journal of Alloys and Compounds | 2005 | 7 Pages |
Abstract
The effect of the monovalent chemical substitution of K+ into Sr2+ sites on the structural, magnetic and electrical properties of La0.6Sr0.4âxKxMnO3 (0 â¤Â x â¤Â 0.15) has been investigated. The rhombohedral distorted perovskite structure with space group R3¯c is observed in this series of materials while the average size ãrAã and Mn3+/Mn4+ ratios are varied simultaneously. The Rietveld refinement of the structure shows that the substitution of Sr by K in the La site changes the structure parameters such as the MnO bond length and MnOMn angles. An increase in the MnO bond length with increasing K content leads to a decrease in the paramagnetic-ferromagnetic transition temperature TC and the metal-semiconductor transition temperature Tp. A magnetoresistance ratio of about 38% at 300 K and in an applied field of 8 T has been observed in the bulk ceramic La0.6Sr0.25K0.15MnO3.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
S. Zemni, Ja. Dhahri, K. Cherif, J. Dhahri, M. Oumezzine, M. Ghedira, H. Vincent,