Observation of Domains in Iron Whiskers Under High Fields

Abstract

An improved instrument utilizing the longitudinal Kerr magneto‐optic effect is used to observe the magnetic domain development in iron whiskers undergoing a magnetization cycle. It is found that domains persist at the tip of the whisker even under conditions for which the crystal is usually assumed to be saturated. Under applied fields of a few thousand oersteds these persistent domains at the tip, in all of the specimens observed, are magnetized perpendicular to the axis of the whisker and in the same sense around its lateral faces. It is proposed that these domains are caused by the high fields localized near the sharp corners and edges of the crystal.