Appliations of amorphous magnetic hall devices

Abstract

Amorphous magnetic materials present a new area of research and provide us with new material for devices. Rare-earth transition metal(RE-TM) amorphous thin films prepared by r.f. sputtering or thermal evaporation have a large extraordinary Hall coefficient ( R 1). We report some characteristics and experimental results of the use of amorphous RE-TM magnetic films as Hall devices. Amorphous magnetic films show various M- H loops, and can be obtained by varying sputtering conditions. All films were used as magnetic heads, but a film with in-plane magnetization was used as a low magnetic field sensor. In hall experiments, 2.5 kBPI signal can be read out using these amorphous films. In Hall sensor experiments, the detectable magnetic field (signal-to-noise ratio, S/N = 1) was about 5 X 10 −3 Oe. Better results in comparison with other Hall sensors were obtained for the temperature dependence of sensitivity and Hall offset voltage.