Gallate single crystal and as well as the piezoelectric element and the piezoelectric sensor for high temperature for the high temperature

摘要

PROBLEM TO BE SOLVED: To provide a material for a piezoelectric device used at a high temperature range, which can be used in the high temperature range exceeding 400°C and has a resistivity thereof whose temperature dependence is low.;SOLUTION: The material is characterized by having a composition selected from the group consisting of RE₃Ga_5-xAl_xSiO₁₄ (wherein RE represents a rare earth, and 0x5), RE₃Ta_0.5Ga_5.5-xAl_xO₁₄ (wherein RE represents a rare earth, and 0x5.5) and RE₃Nb_0.5Ga_5.5-xAl_xO₁₄(wherein RE represents a rare earth, and 0x5.5), and characterized in that a resistivity change in the temperature range of 100 to 600°C is 10⁴ or less. The material is characterized by being produced by: growing a single crystal from a solution in an atmosphere of an inert gas containing an oxidative gas; subsequently lowering the molar fraction (z) of the oxidative gas in the inert gas below the molar fraction of the oxidative gas in the growing process; and cooling the single crystal.;COPYRIGHT: (C)2013,JPO&INPIT