Preparation and magnetic properties of Co-Cr films by toroidal plasma (TP) type sputtering

A sputtering apparatus which can form a stable toroidal plasma has been developed in order to deposit magnetic films with a homogeneous and dense structure and excellent properties under the conditions of low argon gas pressure, low applied voltage, and low substrate temperature of around 30 degrees C. All Co-Cr films deposited by this apparatus were composed of HCP (hexagonal-close-packed) crystallites with c-axis orientation ranging from 8 degrees to 13 degrees . The saturation magnetization varied from 380 to 780 emu/cc, and perpendicular coercivity varied from 100 to 30 Oe. D/sub 50/ of CoCr/Ni-Fe double layer floppy disks was as high as 50 kBPI.<
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