Patent ID: 8728232
Filing Date: 2014-05-20
Classification: C30B

Abstract:
1. A single crystal heat treatment method, comprising a step of heating a single crystal of a cerium-doped silicate compound represented by general formula (1) or (2) below in an atmosphere containing an oxygen concentration of 300 vol ppm or less, at a temperature T 1 (units: ° C.) that satisfies the conditions represented by formula (3) below and at a time of from 1 to 20 hours (wherein Ln represents at least one elemental species selected from a group consisting of elements belonging to the rare earth elements, x represents a numerical value from 0 to 2, and y represents a numerical value greater than 0 but less than or equal to 0.2) (wherein Ln represents at least one elemental species selected from a group consisting of elements belonging to the rare earth elements, z represents a numerical value greater than or equal to 0.4 but less than or equal to 2, and w represents a numerical value greater than 0 but less than or equal to 0.2) (wherein T wherein prior to said step of heating a single crystal of a cerium-doped silicate compound the single crystal is grown or cooled in an oxygen-containing atmosphere, or is heated in an oxygen-containing atmosphere.