Structure tuning and magnetotransport properties in the system (Ba/sub 2-2x/Sr/sub 2x/)FeMoO/sub 6/

The double perovskite alloy system (Ba/sub 2-2x/Sr/sub 2x/)FeMoO/sub 6/ was shown to form a solid solution throughout 0.0 /spl les/ x /spl les/ 1.0. All diffraction peaks can be identified according to a cubic lattice structure on x /spl les/ 0.5 and tetragonal on x > 0.5. Lattice parameters a or c decrease with increasing x. The temperature-dependent component of the resistivity was found to obey an equation of the form by /spl rho/ = /spl rho//sub 0/ + AT/sup n/. The temperature dependence of resistivity changes from n /spl cong/ 1 to n /spl cong/ 2 and Kondo behavior may be observed in lower temperature (/spl les/ 50 K).