Giant magnetotransport and magnetostructural phenomena in hole-doped manganese oxides

Giant magnetotransport phenomena have been investigated for single crystals of perovskite-type La1−xSrxMnO3 and related compounds. Magnetoresistance (MR) with negative sign shows a universal curve as a function of the magnetization, the body of which is quantitatively accounted for by the mean-field theory of the Kondo lattice model with strong ferromagnetic (Hund) coupling. Furthermore, magnetic field-induced structural change has been found between the two types of slightly distorted perovskite structure perhaps due to the strong coupling between the electronic and lattice degrees of freedom in these hole-doped Mn-oxides.