Core-loss analysis of an (Fe, Co, Ni)-based nanocrystalline soft magnetic alloy

Abstract

Nanocrystalline soft magnetic materials possess higher magnetization and operation temperatures than amorphous alloys with similar compositions. For these reasons, they are good candidate materials for power electronics applications. As an indication of their performance, core losses have been measured for a nanocrystalline alloy with the composition Fe64.08Co10.68Ni10.68Zr8.49B4.86Cu1.2 synthesized by a melt-spinning process with subsequent isothermal anneal at 550°C for 1h. The experiments were conducted on toroidal samples using a Walker ac permeameter over a frequency range of 100Hz–500kHz, at induction amplitudes of 100 and 1100mT, at room temperature. A measured toroidal sample possessed a saturation magnetization of 1.529T and core loss of 17.5W∕kg at a frequency of 10kHz and magnetic flux density of 100mT. The Steinmetz analysis of the static hysteresis losses yielded a power-law coefficient of 1.475. A statistical model for excess eddy current losses showed good agreement with experimental results. Excess eddy current losses were found to be the dominant factor in losses above 10kHz for these alloys.