AC MAGNETIZATION ANALYSES IN IRON-RICH AMORPHOUS WIRES

Domain wall depinning and propagation in a long wire of amorphous Fe77.5Si7.5B15 alloy in the as-quenched state are studied during Ac magnetization under a Dc biasing field produced by a solenoid perpendicular to the wire. The active walls undergoing the depinning and propagation are classified into positive and negative ones. Consequently there are alternating and unidirectional magnetic reversal modes, both having two distinct types. The alternating mode can easily be induced by an external magnetic pole equidistant from the wire ends. The experimental data obtained in this work and published elsewhere are discussed in detail. It is concluded that the eventual depinning of the closure domain wall from the end is induced by its elongation and transverse movements. The latter process is essentially the same as domain wall propagation. Both are dynamic with a dominant eddy current damping and domain wall shape-dependent Dc critical field.