Apatite-type silicogermanic acid lanthanum polycrystal, method for producing the same, oxide ion conductor, and solid electrolyte

摘要

PROBLEM TO BE SOLVED: To provide an apatite type lanthanum silicogermanate polycrystalline substance whose crystal axis is oriented in one direction, and has an ionic conductivity, and to provide a production method capable of obtaining the apatite type lanthanum silicogermanate polycrystalline substance without complicated processes.SOLUTION: An apatite type lanthanum silicogermanate polycrystalline substance is obtained by joining a first layer which includes LaSiOas a major component, a second layer which includes La[SiGe]O(wherein, x is a number between 0.01-0.333) as a major component, and a third layer which includes LaSiOas a major component in the order of the first layer/the second layer/the third layer to form a junction material, heating this junction material at a temperature at which element diffusion occurs, and removing the layers except the most intermediate layer among the accumulated layers after heating. There is provided a method of producing the apatite type lanthanum silicogermanate polycrystalline substance.