PNNL

Abstract

Magnetic domain switching and hysteresis loops in a single crystal a-iron with and without nonmagnetic particles were simulated based on the magnetization dynamics of the Landau–Lifshitz–Gilbert equation. It is found that the 360o Bloch domain wall is the easiest nucleation site for an anti-direction domain. The nucleation occurs by splitting the 360o Bloch domain wall into two 180o domain walls. However, the existence of nonmagnetic particles destroys the 180o domain walls and prevents the formation of 360o Bloch domain walls. Simulation results demonstrate that the impact of nonmagnetic particle on the formation of the 360o Bloch domain wall is a magnetic hardening mechanism.