Growth of ${\gamma}-6Bi_2O_3 {\cdot}SiO_2$( Single Crystals by EFG Method

EFG법에 의한 ${\gamma}-6Bi_2O_3 {\cdot}SiO_2$(BSO)단결정의 육성

  • ;
  • ;
  • Kei-Miyamto (Research Institute for Industrial Technique, Osaka)
  • Published : 1991.02.01

Abstract

The fundamental conditions for growing $r-6Bi_2O_3{\cdot}SiO_2$(BSO) single crystal plates by EFG(Edge-defined Film-fed Growth) method, were investigated and characterization, quality test, property measurement were performed for obtained BSO single crystal plates. The opti$\mu$ growing conditions determined in this study were as follows: ${\cdot}$temperature gradient;$24^{\circ}C/cm$ ${\cdot}$pulling rate;2.0mm/h. BSO Single crystal plates grown at the above optimum conditions did not include secondary phase or grain boundary and were confirmed as single crystals by X-ray analysis. IT was found that the single crystal plates had <100> growth direction. G defects, ie pore, void inclusion, striation, were not detected in the single crystal plate under polarizing microscope but dislocations(microscopic defect) were found and dislocation density was $5.1\times10^5/cm^2$.

광기능소자로 응용성이 넓은 전기광학결정 $r-6Bi_2O_3{\cdot}SiO_2$(이하 BSO로 약칭)을 EFG(Edge-defined Film-fed Growth)법에 의하여 판상단결정으로 육성하는 기초적 조건을 조사하고 육성된 판단결정의 characterization 및 평가와 물성측정을 하였다. 본 연구에서 얻어진 최적성장조건은 온도구배가 $24^{\circ}C/cm$, 인상속도는 2.0mm/h이었다. 결정성장 최적조건에서 육성된 BSO결정은 제 2상의 석출이 없고 grain boundary가 존재하지 않으며 X선 분석으로도 단결정임이 확인되었다. 육성된 판상단결정의 판면은 (100)면이었고 결정성장 방위는 <100>이었다. 육성된 판상단결정은 편광현미경하에서는 pore, void, inclusion, striation 등의 성장결함이 없는 양질의 단결정이었으나 미세결함인 전위(dislocation)의 존재가 확인되었고 전위밀도는 $5.1{\times}10^5/\textrm{cm}^2$이었다.

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