Evidence of ferromagnetic domains in the perovskite La_0.7Sr_0.3Co_0.9Mn_0.1O₃

Abstract

The magnetic and electronic ground states of the polycrystalline perovskite compound La_0.7Sr_0.3Co_0.9Mn_0.1O₃ have been studied using AC susceptibility, resistivity and neutron depolarization techniques. Results of neutron depolarization study establish the existence of ferromagnetic domains of ∼3 μm size below 180 K. The substitution of 10 at% Mn ions at the Co site in the compound La_0.7Sr_0.3CoO₃ reduces the effective eg electron transfer and suppresses the double exchange interaction. The competition between the reduced ferromagnetic double exchange interaction and the coexisting antiferromagnetic interaction along with the random nature of substitution leads to a randomly canted ferromagnetic ground state for the substituted compound. Resistivity study confirms that the randomly canted ferromagnetic ground state is insulating.