Temperature dependence of the magnetic properties of amorphous Co-Gd-Mo thin films

RF sputter deposited amorphous Co-Gd-Mo thin films have previously been shown to be potential materials for bubble device applications. However, the operation of a bubble device over a realistic temperature range requires materials with magnetic properties which are relatively temperature insensitive. An assessment of the temperature dependence of the magnetic properties of amorphous Co-Gd-Mo films is reported. The results of a mean field analysis of the magnetization data of Co-Gd-Mo thin films over wide composition and temperature ranges allowed optimization of the film composition for obtaining most suitable temperature dependences of magnetic properties. It has been found that even with the optimum compositions, the degree of temperature insensitivity improves with decreasing bubble diameters and is satisfactory only for sub-half-micron bubble materials. These results and analysis suggest that similar qualitative behavior may also be expected for other transition metal-rare earth alloys.