Homogeneity evaluation of Ca3Ta(Ga0.5Al0.5)3Si2O14 single crystal by the line-focus-beam ultrasonic material characterization system

A new method for evaluating homogeneities of Ca
₃
Ta(Ga
_0.5
Al
_0.5
)
₃
Si
₂
O
₁₄
(CTGAS) single crystal was investigated using leaky surface acoustic wave (LSAW) velocities measured by the line-focus-beam ultrasonic material characterization (LFB-UMC) system. LSAW velocity changes due to Al-substitution effect were successfully extracted by using a relationship between two LSAW velocities propagating along different directions for Ca
₃
TaGa
₃
Si
₂
O
₁₄
(CTGS) and Al-doped CTGS. Al-concentration variation of 0.219 at% was detected in diameter direction of the crystal ingot through the LSAW velocity measurements for Y-cut CTGAS specimen. The velocity resolution to Al-concentration is estimated to be ±0.0046 at% for Y-cut Z-propagating LSAW.