Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9837316 | Physica B: Condensed Matter | 2005 | 8 Pages |
Abstract
The crystal structure and magnetic properties of a series of ordered double perovskite oxides (Sr2â3xLa2xBax)FeMoO6 (0⩽x⩽0.3) have been investigated. X-ray powder diffraction reveals that the crystal structure of the compounds changes from a tetragonal I4/m lattice to a cubic Fm3¯m lattice around x=0.2. Though the nominal average size of the A site cation of (Sr2â3xLa2xBax)FeMoO6 is designed to be almost independent of x, the refinements of the crystal structure show that the lattice constants increase with x in both the tetragonal and the cubic phase regions due to electron doping. As the x increases, the degree of cationic ordering on the B site is decreased pronouncedly, while the Curie temperature of the compounds is nearly unchanged. The saturation magnetization of the compounds decreases with x and shows a linear dependence on the degree of cation ordering. The resistivity of the parent compound shows a semiconducting behavior below room temperature, but those of the doped samples exhibit a metal-semiconductor transition. A correlation between the resistivity and metal-semiconducting transition temperature (TMâS) is observed. The resistivity and TMâS of the compounds decrease with x for x⩽0.2 and increase for x⩾0.2. Magnetoresistance of the compounds is reduced by the La/Ba doping. All these observations can be understood based on the interplay of the electron doping, change in bandwidth and the anti-site defect concentration.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Q. Zhang, G.H. Rao, H.Z. Dong, Y.G. Xiao, X.M. Feng, G.Y. Liu, Y. Zhang, J.K. Liang,