비정질 탄산칼슘을 이용한 편광소자용 Calcite 단결정의 성장 및 특성평가
Growth and characterization of calcite single crystal using polarized device with amorphous calcium carbonate
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초록
물에 대한 용해도가 우수한 비정질 탄산칼슘을 이용하여 저온 영역에서 Calcite 단결정을 수열육성 하였다. 비 정질 탄산칼슘 제조의 출발원료로는 CaCl2 및 Na2CO3를 이용하였으며, 반응온도와 반응시간이 중요한 인자로 작용하였다. 한편, 중량손실법에 의한 비정질 탄산칼슘의 용해도 측정결과 NH4NO3 수용액이 Calcite 결정성장에 효과적임을 알 수 있었 다. Calcite 결정의 육성에 있어 큰 성장속도를 나타내는 수열조건은 다음과 같다. 즉, 출발원료: 비정질 탄산칼슘, 수열용매: 0.01m NH4NO3, 반응온도: 180oC, 반응시간: 30일 이었다. 이와 같은 조건하에서 얻어진 Calcite 단결정은 전위밀도: 106~ 107cm-2, 투과율: 190~400nm 범위에서 약 80%, 복굴절율: 0.17~0.18 이었으며, HCO3- 및 OH- 이온의 혼입에 의한 광학적 흡수가 발생하지 않음을 FT-IR 분석 결과로부터 알 수 있었다.
Abstract
The crystal growth of calcite at a low temperature range was carried out by the hydrothermal method usingamorphous calcium carbonate which has excellent solubility in water. Amorphous calcium carbonate was prepared by thewet chemical reaction of a stoichiometric mixture of CaCl2 and Na2CO3. An important factor was the reaction temperaturemethod, NH4NO3 solutions were found to be the most promising solvents to grow calcite single crystals. The hydrothermalconditions for high growth rates of calcite single crystals were as folows: starting material: amorphous calcium carbonate,solvent: 0.01 m NH4NO3, temperature: 180oC, duration: 30 days. And properties of calcite single crystals were folows:dislocation density: 106~107 cm2, UV-visible transmittance: about 80 % from 190 to 400 nm and birefringence: 0.17~0.18.Also, it can be known from the FT-IR results that the absorption peak by injection of HCO3 and OH ions was not shown.Key words Amorphous calcium carbonate, Hydrothermal method, Calcite single crystal, Polarization device
참고문헌 (10)
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