Yttria-stabilized zirconia (YSZ) has a low thermal conductivity, high thermal expansion coefficient, and excellent mechanical properties; thus, it is used as a thermal barrier coating material for gas turbines. However, during long-time exposure of YSZ to temperatures of 1200oC or higher, a phase transformation accompanied by a volume change occurs, causing the YSZ coating layer to peel off. To solve this problem, YSZ has been doped with trivalent and tetravalent oxides to obtain coating materials with low thermal conductivity and suppressed phase transformation of zirconia. In this study, YSZ is doped with trivalent oxides, Nd2O3, Yb2O3, Al2O3, and tetravalent oxide, TiO2, and the thermal conductivity of the obtained materials is analyzed according to the composition; furthermore, the relative density change, microstructure change, and m-phase formation behavior are analyzed during long-time heat treatment at high temperatures.

Abstract
1. 서 론
2. 실험 절차
3. 실험 결과 및 논의
4. 결 론
감사의 글
References

• 이계원(한국세라믹기술원 이천분원 엔지니어링소재센터, 고려대학교 신소재공학과) | Gye-Won Lee (Engineering Materials Center, Korea Institute of Ceramic Engineering and Technology, Department of Materials Science and Engineering, Korea University)
• 최용석(한국세라믹기술원 이천분원 엔지니어링소재센터, 고려대학교 신소재공학과) | Yong-Seok Choi (Engineering Materials Center, Korea Institute of Ceramic Engineering and Technology, Department of Materials Science and Engineering, Korea University)
• 전창우(한국세라믹기술원 이천분원 엔지니어링소재센터) | Chang-Woo Jeon (Engineering Materials Center, Korea Institute of Ceramic Engineering and Technology)
• 이인환(고려대학교 신소재공학과) | In-Hwan Lee (Department of Materials Science and Engineering, Korea University)
• 오윤석(한국세라믹기술원 이천분원 엔지니어링소재센터) | Yoon-Suk Oh (Engineering Materials Center, Korea Institute of Ceramic Engineering and Technology) Corresponding author