Magneto-optical Kerr effect and magnetization structure of permalloy microparticles under mechanical stress

In this work, changes in the domain structure of planar permalloy microparticles under mechanical stress have been studied. For this purpose, an array of particles under mechanical stress has been formed on the silicon substrate. In addition, samples with an array of unstressed particles have been made. Using the samples, the magnetic structure has been visualized by magnetic force microscopy and hysteresis loops have been obtained by the method of magneto-optical Kerr effect. It has been found that an easy magnetization axis appears in the stressed samples due to uniaxial anisotropy caused by the mechanical stress of the particles. The axis direction coincides with the direction of particle compression. At the same time, the distribution of magnetization observed in the unstressed particles is determined mainly by the shape anisotropy.