Role of magnetostriction on power losses in nanocrystalline soft magnets
Hiroshi Tsukahara, Hiroshi Imamura, Chiharu Mitsumata, K. Suzuki, Kanta Ono
Abstract
Abstract Soft magnetic materials are key materials for the magnetic cores used in motors and generators. To improve the energy efficiency of magnetic cores, it is important to understand the mechanism of energy loss under oscillating magnetic fields. Here, we clarify the mechanism of energy loss in nanocrystalline soft magnetic materials (NSMMs), which are candidates for energy-efficient magnetic cores. To investigate the energy loss of an NSMM, it is necessary to consider the interaction between the magnetization and the crystal lattice, i.e., magnetostriction. However, the random distributions of crystalline axes in nanocrystals hinder magnetostriction calculation. We developed a micromagnetic simulation program by formulating the effective fields due to magnetostriction in randomly oriented nanocrystallites. We performed micromagnetic simulations of NSMMs under an oscillating magnetic field and found that the magnetic energy of the moving domain wall dissipates into the elastic energy of the crystal lattice through magnetostriction. These results can enable the design of highly energy-efficient NSMMs.