Domain Observations on Iron Whiskers

Abstract

Ferromagnetic domain walls have been observed by standard methods on iron whiskers. The whiskers are square in cross section, generally 20 to 60 microns on a side, and up to one cm long. The whiskers are single crystals with the axis in a 〈100〉 direction and the faces nearly perfect {100} planes. The domain patterns are exceptionally clear and simple. Several characteristic patterns have been described and represented with three-dimensional models; a feature common to many patterns is the V line, which consists of two plane walls meeting in a V with its apex at the whisker surface. The effects of applied fields and applied stresses on the domain structures have been studied, and some observations have been made on whiskers small enough to approach a single-domain state.