Chalorimetry of high temperature form of cubanite

Research Project

Project/Area Number	61540594
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	鉱物学(含岩石・鉱床学)
Research Institution	Faculty of Engineering, Yamaguchi University
Principal Investigator	MIZOTA Tadato Yamaguchi University, 工学部, 助教授 (10018666)
Co-Investigator(Kenkyū-buntansha)	SHIMA Hiromi Yamaguchi Universty, 工学部, 教授 (70035038) FUJII Yujiro Yamaguchi University, 工学部, 教授 (00035023)
Project Period (FY)	1986 – 1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥2,200,000 (Direct Cost: ¥2,200,000) Fiscal Year 1987: ¥300,000 (Direct Cost: ¥300,000) Fiscal Year 1986: ¥1,900,000 (Direct Cost: ¥1,900,000)
Keywords	adiabatic calorimeter / cubanite / heat capacity / glassy transition / high cubanite / 高温型キューバ鉱 / 熱容量異常 / GP-IB
Research Abstract	Cubanite transforms to high temperature cubic form above 220 C. Calorimetric investigations had been done for the high form which shows anomaly in heat capacity (Mizota et al., 1985). The transition has been explained to be due to glassy transition of metal atoms (Cu anf Fe) in high cubanite, but the proof has not been enough for the sake of calorimetric limitations at that stage of investigation. The present investigation was initiated to clarify the origin of the anomaly of heat capacity revieled between 170 and 300 C. New Type of a small scale adiabatic calorimeter has been developped through the present project. Cubanite sample sealed at low pressure with He in a glass ampoule was supplied for the calorimetric mesurement. The results show no heat relaxation nor heating rate dependency, which indicates the transition belongs to the reversible type caused from metal vibration at elevated temperature above 170 C. The adiabatic calorimeter can be used for various samples which are difficult to obtain enough amount of materials.