METHOD AND APPARATUS FOR PRODUCING LANGASITE-BASED SINGLE CRYSTAL AND COMBUSTION PRESSURE SENSOR OBTAINED BY USING THE SINGLE CRYSTAL

PROBLEM TO BE SOLVED: To provide a method, by which it becomes possible to solve the problem of generation of drift that is found when a langasite-based single crystal is used to produce a combustion pressure sensor or the like, and the detection accuracy, stability, and reliability can be drastically enhanced. SOLUTION: When a langasite-based single crystal is produced by arranging a crucible under a heating environment having a temperature gradient in a vertical direction in an inert gas atmosphere, filling a seed crystal in the crucible, then filling a raw material on the seed crystal, and after heating and melting a portion of the seed crystal and raw material, moving the crucible at least vertical direction to produce the same, the heating environment is constituted by using a carbon heating element, an inert gas atmosphere in which the content of an inert gas is about 100% is formed by supplying the inert gas to the heating environment, and the crucible is arranged in the inert gas atmosphere. Thereby, the langasite-based single crystal having electrical resistivity of ≥1012Ωcm under a temperature environment of 175°C can be produced. COPYRIGHT: (C)2008,JPO&INPIT