Growth and physical properties of Al doped Ca3NbGa3Si2O14 piezoelectric single crystals

Ca
₃
Nb(Ga
_1-x
Al
_x
)
₃
Si
₂
O
₁₄
(CNGAS) crystals with various Al concentrations were grown by a micro-pulling-down (μ-PD) method and their crystal structures, chemical compositions, crystallinities were investigated. CNGAS crystals with x = 0.2, 0.4 and 0.6 indicated a single phase of langasite-type structure and the crystals with x = 0.8 and 1 included some secondary phases in addition to the langasite-type phase by the powder X-ray diffraction measurements. Lattice parameters, a and c-axes lengths, of the langasite-type phase systematically decreased with an increase of Al concentration.