Chalorimetry of high temperature form of cubanite

古巴长石在220℃以上转变为高温立方形态，热量学研究表明高温形态的热容量异常（Mizota et al., 1985）。这种转变被解释为由于金属原子（Cu和Fe）在高cubanite中的玻璃化转变，但由于当时研究阶段的量热限制，证明还不够。本研究的目的是澄清170 ~ 300℃热容异常的原因，通过本项目研制了一种新型的小型绝热量热计。在低压下用He密封在玻璃安瓿中的古巴石样品用于量热测量。结果表明，在170℃以上的高温下，该相变属于由金属振动引起的可逆型。绝热量热计可用于各种难以获得足够量材料的样品。

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.