Growth and Electric Properties of Al-Substituted Langasite-Type La3Ta0.5Ga5.5O14 Crystals at High Temperature
We report an effective substitution of aluminum for gallium in langasite-type La3Ta0.5Ga5.5O14 (LTG) crystals for use in a pressure sensor at high temperature. Al-substituted LTG (La3Ta0.5Ga5.5-xAlxO14; LTGAx) single crystals up to the solubility limit of x=0.5 have been grown by the conventional Czochralski technique. The electric properties of the LTGAx crystals were investigated and compared with those of LTG. By Al substitution, the piezoelectric constant d11 and the electromechanical coupling factors (k12) became slightly larger. The LTGAx crystals showed a lower temperature dependence of d11 and a higher electric resistivity ρ than those of the LTG crystals.
Keiichi Katayama, Kazumi Kato, Tadashi Takenaka, Masasuke Takata and Kazuo Shinozaki
H. Takeda et al., "Growth and Electric Properties of Al-Substituted Langasite-Type La3Ta0.5Ga5.5O14 Crystals at High Temperature ", Key Engineering Materials, Vol. 320, pp. 239-242, 2006