| 摘要 |
PROBLEM TO BE SOLVED: To decrease production of dust by constituting the spacer ring of a ceramic material at least the outer circumference part of which is coated with a coating film. SOLUTION: A spacer 21 for magnetic disks consists of a spacer ring of a ceramic material at least the outer circumference of which is covered with a coating film 24. The coating film 24 is preferably made of silicon, carbon, transition metal elements or transition metal alloy. As transition metals, tungsten, titanium, cobalt, iron, nickel, zirconium, tantalum, copper, silver, gold or the like is used. The spacer 21 made of a ceramic material is dipped in an alkali liquid, acidic liquid or alkali or acidic liquid with addition of a surfactant, and dried. Preferably, the alkali liquid is controlled to the range of 10 to 14 for pH, while the acidic liquid is controlled to the range of 0 to 4 for pH. When a surfactant is added, its concn. is controlled to the range of 0.001 to 10 wt.%.
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