Simultaneous magnetic force microscopy imaging of perpendicular and in-plane magnetic field gradient on La_(0.7)Sr_(0.3)MnO_3 granular film with in-plane magnetization

摘要

Our recently developed magnetic force microscopy for simultaneous imaging of perpendicular and in-plane magnetic field gradients was applied to polycrystalline La_(0.7)Sr_(0.3)MnO_3 granular films with in-plane magnetization. The present method clearly imaged the gradient of the perpendicular and the in-plane magnetic field from the boundary phase, which behaved as a magnetic double layer with two separate planes of magnetic charges. Especially after magnetizing the film in one direction, the perpendicular and in-plane magnetic field gradients of a magnetic double layer with opposite-sign magnetic charges were clearly observed by this method. Calculated magnetic field gradients are consistent with those of the magnetic force microscopy images. The present method seems to be effective in evaluating the magnetic isolation between neighboring magnetic grains having the component of in-plane magnetization.