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.

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

• 조재영(한국세라믹기술원 소재융합고도화본부 디스플레이소재센터,경북대학교 자연과학대학 물리학과) | Jaeyoung Cho (Display Materials Center, Korea Institute of Ceramic Engineering & Technology,Department of Physics, Kyungpook National University)
• 김진호(한국세라믹기술원 소재융합고도화본부 디스플레이소재센터) | Jinho Kim (Display Materials Center, Korea Institute of Ceramic Engineering & Technology)
• 김세훈(강릉원주대학교 세라믹신소재공학과) | Sae-Hoon Kim (Department of Ceramic Engineering, Gangneung Wonju National University)
• 이미재(한국세라믹기술원 소재융합고도화본부 디스플레이소재센터) | Mijai Lee (Display Materials Center, Korea Institute of Ceramic Engineering & Technology) Corresponding author