Anomalous Heat Capacities and Structure Changes in Phase Transition of Silicate Minerals

用绝热水合热法和X-射线粉末衍射法研究了各种阳离子交换合成A型沸石和一些天然沸石的水化机理。研究发现，某些沸石物种适合作为沸石-水对热泵系统的换热吸收剂。(2)利用本项目引进的进动DSC(TA-Instrument Model2910型)研究了硅酸盐和某些硫化物矿物的热容异常。例如，围绕无公度-NORML相变澄清了阿克曼石热容量异常。(3)合成了Cu3BiS3和AgBi3S5等离子导体，测量了离子传导-转变温度附近的热容，解释了转变机理。还合成了单晶，以备高精度的X射线结构分析。(4)合成了光致发光材料Zn_2SiO_4的单晶，并对其晶体结构进行了分析，给出了锌、硅原子的部分无序化。采用干法合成了一种新型发光材料Ba2(TiO7)[Si2O7]。

Variously cation-exchanged synthetic A-type zeolites and some natural zeolites have been investigated in hydration mechanisms by using the adiabatic hydration calorimeter method and X-ray powder diffraction. Some zeolite species investigated were found suitable for heat exchange absorbent for a heat pump system of the zeolitewater pair. (2) Precession DSC (TA-Instrument Model 2910) introduced in the present project were used for investigating heat capacity anomalies in silicate and some sulfide minerals. Akermanite heat capacity anomalies were clarified around the incommensurate-norml phase transition, for example. (3) Ionic conductors such as Cu3BiS3 and AgBi3S5 were synthesized, and measured in heat capacities around ionic conduction-transition temperatures to explain transition mechanisms. Single crystals were also synthesized for preparation of precise X-ray structure analysis. (4) Single crystals of a photo-luminescent material, Zn2SiO4, was synthesized and analyzed in the crystal structure to give partial disordering of Zn and Si atoms. A new luminescent material, Ba2 (TiO) [Si2O7], was found and synthesized in dry method.