Structural, magnetic and electrical transport properties of Co doping in LaKFeMoO6 double perovskite

Abstract The structural, magnetic and transport properties of La 1+ x K 1− x Fe 1− y Co y MoO 6 (0.0≤ x ≤0.1 and 0.1≤ y ≤0.2) series are studied. At room temperature, the crystal structure is a monoclinic system with space group P 2 1 / n . The antisite defect lowers with Co doping in LaKFe 1− y Co y MoO 6 series. However, it increases with the substitution of K by La. Magnetizations increase with the increase in Co content ( x =0) and with the La substitution for K, respectively. All compounds demonstrate semiconducting behavior. Their electrical resistivities increase with Co content for LaKFe 1− y Co y MoO 6 and also increase with La for La 1+ x K 1− x Fe 1− y Co y MoO 6 . For the LaKFe 1− y Co y MoO 6 the electrical transport behavior can be described by Mott variable range hopping model in the studied temperature range, whereas for the La 1+ x K 1− x Fe 1− y Co y MoO 6 ( x ≠0 and y ≠0) the electrical transport behavior follows the Mott and ES variable range hopping model in high and low temperature ranges, respectively. Each sample exhibits a large magnetoresistance effect.