Magnetic Transition of La_(0.8)Sr_(0.2)Mn_(1-x)Co_xO_3 (x=0,0.3, 0.5,1.0)

摘要

A series of rare earth compound oxides with the formula of La 0.8 Sr 0.2 Mn 1-x CoxO3 （x=0.0, 0.3, 0.5, 1.0） were prepared by the method of citric acid. Structures, figures and magnetic properties of the samples were analyzed by means of XRD, SEM and SQUID. Experiment results prove that all the samples are hexagonal, but their figures and magnetic properties are different. La 0.8 Sr 0.2 MnO3 is ferromagnetic. La 0.8 Sr 0.2 Mn 0.7 Co 0.3 O3 and La 0.8 Sr 0.2 Mn 0.5 Co 0.5 O3 are ferrimagnetic. La 0.8 Sr 0.2 CoO3 is antiferromagnetic. SEM results indicate that the structure of the first three are three-dimensional reticulations which are made up of some small ellipsoids which link up at the head and the end. The fourth sample looks like some dispersed small balls.