| 摘要 |
PROBLEM TO BE SOLVED: To obtain a glass substrate having enough mechanical strength, chemical stability and light transmitting property by dispersing fine particles containing specified rare earth elements in a specified range of amt. in a glass phase. SOLUTION: On a glass substrate 1 having 65mm diameter, a 25-nm thick Cr precoating film 2, 50-nm thick Cr base film 3, 50-nm thick CoCr magnetic film 4, and 10nm thick carbon protective film 5 are deposited in this order, and then a texture 6 is formed by etching. Further a lubricant film 7 is applied to constitute a magnetic disk. The glass substrate 1 is prepared by dispersing fine particles comprising Ln203 oxide of one or more rare earth elements selected from Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. The average grain size of the fine particles is 1 to 100nm. The rare earth elements are included by 0.5 to 20wt.% calculated as oxides to the whole glass. |
