RECORDING PROPERTIES OF CO-NI OBLIQUELY EVAPORATED TAPE

This paper describes the recording properties of Co-Ni obliquely evaporated tape (ME tape) when a ring head is used. Since an isolated playback pulse identifies the magnetization transition region, we investigated the variation of phase characteristics of isolated pulses with tape-transport direction and with the magnetic motive force (MMF) of the recording head. Fast Fourier transformation is used to make a quantitative analysis of the phase distortion. It was found that the phase distortion of ME tape depends on the tape-transport direction during recording, but not during playback. The degree of inclination of the magnetization vector was estimated from the phase distortion in the low-frequency region. When recording was performed in the normal direction, the inclination of the magnetization vector was estimated to be 20-degrees, and 25-degrees in the reverse direction. In normal-direction recording, the phase distortion of the isolated pulse was independent of MMF and remained constant. That is to say, the magnetization vector in the normal direction is very stable. An analysis of recording properties which assumed the magnetization of uniaxial anisotropy particulates suggested that the magnetization vector should be oriented near the easy-axis direction.