X-ray topography of piezoelectric LaTaGaO crystal grown by Czochralski method

Yoneda, Yasuhiro; Mizuki, Junichiro; Takeda, Hiroaki*; Shiosaki, Tadashi*

IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 55(5), p.971 - 974, 2008/05

We performed synchrotron X-ray topography on a LaTaGaO (LTG) crystal grown by the Czochralski (Cz) method. Since the synchrotron X-ray source can provide high-energy X-rays, one can detect bulk-sensitive information by the X-ray topography. LTG is one of the most attractive piezoelectric crystals like LaGaSiO (LGS), because of excellent acoustic properties (temperature compensation of acoustic losses). Since LTG single crystals can be grown from stoichiometric melt, single crystals with good crystal quality can be obtained comparing to LGS which can not be grown from stoichiometric system but from congruent melt. The 60-keV X-ray topography revealed that the LTG crystal quality was not the same crystalline quality. The crystal quality of a center parts was worse than that of surroundings.