Structural, electronic, and magnetic properties of Sr2-xBaxFeMoO6(0 <= x <= 2)

Abstract

Here we report on the investigation of structural, transport, and magnetic properties,in double perovskite system, Sr2-xBaxFeMoO6(0 <= x <= 2). X-ray Diffraction analysis shows that the compounds form in single phase across the whole solid solution range. The Rietveld refinement of the x-ray data clearly indicates a structural transition from tetragonal (I4/m) for x <= 0.6 to cubic (Fm3m) for x >= 1.6 with an orthorhombic (Fmmm) structure in the intermediate region (0.8 <= x <= 1.4). Magnetization studies show a regular increase in saturation magnetization from 2.0 mu B/f.u.(x=0) to 30 mu(B)/f.u.(x=2) with increasing Ba concentration. However, magnetization as well as electron-spin resonance (ESR) measurements confirmed a systematic decrease in the Curie temperatures from 420 K (x=0) to 310K (x=2) with increasing x. Resistivity measurements carried out in zero magnetic field and for a field of 0.8 T reveal appreciably higher magnetoresistance for intermediate compositions in comparison to those at the ends. (c) 2005 American Institute of Physics.