Nanoscale magnetic-domain structure in colossal magnetoresistance islands

Magnetic force microscopy reveals the nature of local magnetic structure in submicron islands of colossal magnetoresistance (CMR) thin films. The evolution of domains in a magnetic field reveals the importance of shape anisotropy as well as magnetostriction in determining the micromagnetics in such small CMR structures. At room temperature, a characteristic multidomain structure with perpendicular orientation, predicted by theory, is observed. The magnetization reversal of the islands in magnetic fields perpendicular and parallel to the substrate is dominated by strong domain wall pinning. Strong domain wall pinning in conjunction with geometrical confinement in these submicron CMR structures gives rise to reproducible multidomain structure.