Imperfections in <TEX>$LiTaO_3$</TEX> Crystal

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J. Korean Ceram. Soc. > Volume 31(2); 1994 > Article

Journal of the Korean Ceramic Society 1994;31(2): 147.

$LiTaO_3$ 단결정의 결함

김한균, 박승익, 박현민, 정수진

서울대학교 무기재료공학과

Imperfections in $LiTaO_3$ Crystal

ABSTRACT

The imperfections of LiTaO3 crystals grown from the Pt-Rh and the Ir crucible were investigated with X-ray diffraction, optical and electron microscope. The growth direction was <100>h and the plane parallel to the plane connecting two main growth ridges was (012)h which would be the main cleavage plane. The dislocation density in the specimen cut parallel to (012)h plane increased with polishing time and the inverted ferroelectric microdomains were induced based on this dislocations. Such imperfections as 180$^{circ}$ domains, microcracks, dislocations and stacking faults. could be found in the LiTaO3 crytals. The crystal contaminated with lots of Rh form Pt-Rh crucible during the crystal growing under air atmosphere contained more imperfections. The main cleavage plane and subgrain boundary parallel to its growing axis might be the main source of reducing the mechnical strength during the wafering process.