| 摘要 |
PURPOSE:To improve the durability of a thin film gamma-iron oxide magnetic recording medium, which contains respectively prescribed amts. of copper, titanium and cobalt, without spoiling the S/N characteristic thereof by incorporating the copper in the smaller concn. in the surface layer and in the larger concn. in the depth direction of the film thickness. CONSTITUTION:The 1st layer 2 of an a-Fe2O3 film contg. much, for example, 1.5% copper is formed on a substrate 1 to about 0.8mum thickness by a sputtering method, then the 2nd layer 3 of an a-Fe2O3 film contg. less, for example, 0.1% copper is formed thereon to about 0.08mum thickness likewise by a sputtering method. Titanium and cobalt are of course added in prescribed amt. therein. The substrate 1 constituted in such a way is subjected to reducing, oxidizing and heat treating stages, by which the thin gamma-Fe2O3 film of a magnetic recording medium is formed. The S/N characteristic among the characteristics that such magnetic recording medium possesses decreases by about 2db as compared to a magnetic recording medium of a single layered film contg. 1.5% copper but in a durability test the above-mentioned medium withstands 4,000 cycles of low-speed durability tests for sliding movement as compared with the single layered film which is flawed after about 100 cycles. |
