Nippon Telegraph and Telephone Corporation

Takao Ishii

Shintaro Miyazawa

Yasuo Tazou

Tsunekazu Iwata

Yukimichi Tajima

An LiGaO.sub.2 single crystal manufactured by the Czochralski method has a crystallographic axis as a pulling direction set within an angle range of 30.degree. from a b- or a-axis direction. An LiGaO.sub.2 single-crystal substrate and a method of manufacturing the single crystal and the substrate are also disclosed.

LiGaO.sub.2 single crystal, single-crystal substrate, and method of

Method of manufacturing a LiGaO.sub.2 single-crystal substrate

The present invention relates to an oxygen ion conductor consisting of a composition consisting of (1-x-y)ZrO.sub.2 --xSc.sub.2 O.sub.3 --yAl.sub.2 O.sub.3, and to solid fuel cells employing this ion conductor as the solid electrolyte. In order to obtain more desireable characteristics in the aforementioned composition, it is preferrable to apply limits to the composition such that: 0.05&lt;x+y.ltoreq.0.16 and x&gt;0, y&gt;0, or, alternatively, such that: 0.07.ltoreq.x+.ltoreq.0.13 and 0.005.ltoreq.y.ltoreq.0.02. In the present invention phase transitions occuring during temperature change from room temperature to high temperatures are eliminated and mechanical strength with respect to the heat cycle is increased by adding as a secondary dopant a specific quantity of Al.sub.2 O.sub.3 to a specific ZrO.sub.2 --Sc.sub.2 O.sub.3 system composition which has a high degree of ion conductivity.

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Kanagawa, Japan

Takao Ishii