Flux Reversal in Ferrite Cores under the Effect of a Transverse Field

Abstract

It is known that flux reversal in ferrites involves three switching mechanisms, namely, domain wall motion, nonuniform rotation, and uniform rotation. The experimental results presented in this paper demonstrate that a steady transverse field in conjunction with set and reset pulses is capable of separating these mechanisms into three regions of flux dispersion. Each region is designated by flux components φ₁, φ₂, and φ₃ with corresponding characteristic transverse fields H ₁, H ₂, and H ₃. The output waveform of the longitudinal sense signal during flux reversal is characterized by its first peak, second peak, and the long tail. The 50% value of the second peak occurs at the same characteristic transverse field H ₂. The transverse field has no appreciable effect on their distribution. The experimental results agree with theoretical predictions in which less flux is switched by domain wall motion at higher drive currents. Furthermore, a proper transverse field has the effect of speeding up the switching time of a ferrite core without sacrificing the amplitude of the output signal due to the fast reversal mechanisms.

This work was supported by the Bureau of Ships, U. S. Navy.