| 摘要 |
<p>A translucent ceramic comprising, as the main component, a tungsten-bronze-type compound represented by the general formula [(Sr,Ba)Nb<SUB>v</SUB>O<SUB>w</SUB>] [wherein v represents a number ranging from 1.8 to 2.2 inclusive, and w represents a positive number which can keep the compound electrically neutral], wherein some of the Nb molecules are independently substituted by at least one element (M) selected from Zn and Mg and the mole-based ratio of the substitution is 0.004 or greater. Preferably, the translucent ceramic contains at least one member selected from Sn and Bi in an amount of 0.15 part by weight or more in terms of SnO<SUB>2</SUB> and Bi<SUB>2</SUB>O<SUB>3</SUB>, respectively, relative to 100 parts by weight of the main component, and the molar ratio of Ba in the (Sr,Ba) site ranges from 0.25 to 0.50. Also preferably, the translucent ceramic contains Na or La in an amount of less than 25 parts by moles or less than 11 parts by mole, respectively, relative to 100 parts by mole of the sum total of Sr and Ba. It becomes possible to provide a translucent ceramic which is inexpensive and is useful as an electrooptical material, and to provide an electrooptical part (e.g., an optical switch, an optical shutter) using the translucent ceramic.</p> |
