한국재료학회지 제32권 제9호 (p.379-383)

BaO-GeO2-La2O3-ZnO 계에 있어서 BaO 첨가량 변화에 따른 광학 특성

Optical Properties according to BaO Addition for BaO-GeO2-La2O3-ZnO System
키워드 :
bao-geo2 glass,tg,knoop hardness,abbe number.

목차

Abstract
1. 서 론
2. 실험방법
3. 결과 및 고찰
4. 결 론
Acknowledgement
References

초록

In this study, Barium Germanium glasses were prepared with a composition of xBaO-(72-x)GeO2-8La2O3-20ZnO where x = 16.0, 18.0, 20.0, 22.0 and 24.0 mol% respectively. Their physical and optical properties, such as refractiveness index, glass transition temperature (Tg), softening temperature (Ts), transmittance and Knoop hardness were studied. The results showed that refractive index, Tg, Ts and coefficient of thermal expansion (CTE) increased with increasing BaO concentration. The refractive index of all the prepared samples was observed between 1.7811 to 1.7881. The Abbe number was calculated by formula using nd (589.3 nm), nf (656.3 nm) and nc (486.1 nm) and observed to be between 38 to 40. The Abbe number of the prepared sample was similar to that of BaO and GeO2. The transmittance of the prepared glasses was observed to be between 80 ~ 82 % throughout the range from 200 nm to 800 nm. Knoop hardness divided into seven steps were measured 5 class (≥ 450 ~ < 550) of all prepared samples.