An Introduction to Magnetic Recording Heads

Abstract

Magnetic recording heads are used for writing and reading data on magnetic recording media, typically in the form of magnetic hard disks, floppy disks or tape. The earliest recording heads consisted of toroids of metallic ferromagnets with a few turns of wire around them, as schematically illustrated in Fig. 1. However, the metals did not perform well at high frequency, because of eddy currents induced in them when their magnetization changed. As a result the metallic ferromagnets were replaced by magnetically soft ferrites, such as NiZn-ferrite and MnZn-ferrite, because the ferrites were insulators and therefore not limited in performance by the effects of eddy currents.