Magnetic properties and magnetoresistance effect of La2Co1−xMg xMnO6 (0.1 ⩽ x ⩽ 1.0)

Abstract

Double perovskite La2Co1−xMgxMnO6 samples with different compositions (x = 0.1, 0.2, 0.3, 0.5, 0.7, 1.0) were synthesized by the standard solid-state reaction method. The samples (x = 0.1, 0.2, 0.3, 0.5, 0.7) exhibit obvious ferromagnetic behavior. The remanent magnetization, coercive field and Curie temperature gradually decrease with increasing the Mg-substitution. The appropriate amount of Mg-substitution can increase the saturation magnetization. The types of interactions changed with Mg-substitution, which makes the La2MgMnO6 sample exhibit clear antiferromagnetism. A slightly enhanced negative magnetoresistance effect (approximately 17%) of the La2Co0.9Mg0.1MnO6 sample was observed at 200 K and 7 T. The pronounced linear magnetoresistance effect is attributed to the suppression of spin-fluctuations by the magnetic field.