Thermomagnetic contact printing in amorphous Tb-Fe films

Ferrimagnetic amorphous Tb-Fe films prepared by rf sputtering or thermal evaporation have a perpendicular anisotropy, a low Curie point (Tc) and large values of coercivity (Hc) over a wide range of temperature. This paper describes the effect of thermal annealing and the contact printing method by Curie point writing for visual display of magnetic information recorded on magnetic tapes or discs. The values of Hc, Tc and the room temperature magnetization (Ms) are reduced by thermal annealing. Thermomagnetic contact printing in an amorphous Tb-Fe film has been tried. It is accomplished by putting the film on the recorded magnetic tape or disc and then heating up the film by photoflash light. The information is observed by means of the polar Kerr effect. In this printing method high resolution printing is realized and analog printing is possible.