Semiconductive ceramics and supporting member made of the same for supporting magnetic disk substrate
AssigneeKYOCERA Corporation
InventorsTetsuji Hayasaki, Masahiro Okumura
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Abstract
A semiconductive ceramic contains a compound of MgO and SiO.sub.2 as a main component, and an iron oxide such as FeO, Fe.sub.2 O.sub.3, and Fe.sub.3 O.sub.4 as an electric conductivity provider. According to necessity, the semiconductive ceramic further contains at least one of zinc oxide, niobium oxide, and chromium oxide as an electric conductivity provider. The semiconductive ceramic has a desired electric conductivity and a mechanical strength required for structural material, thus being usable in various applications.
Claims7
A supporting member for supporting a magnetic disk substrate, the supporting member being made of a semiconductive ceramic comprising a compound of MgO and SiO.sub.2 as a main component, an iron oxide and at least one selected from the group consisting of a zinc oxide, a niobium oxide, and a chromium oxide, and having a three-point bending strength of 100 MPa or more and a thermal expansion coefficient of 11.times.10.sup.-6 /.degree. C. or less.
Dependencies are inferred from the claim text.