Development of Microcalorimetry

许多量热法之所以能得到准确的数据，部分原因在于实验中使用了大量纯化的样品。随着新材料的合成和表征方法的发展，需要小型化各种类型的量热计来进行热力学表征。本研究项目的目的是使各种反应和非反应量热计小型化，以进一步发展热科学，而不损失所得到的量热数据的准确性和精密度。研制了一种低温绝热微量热计，使用小于1g的少量试样测定第三定律熵成为可能。对激光闪光量热计进行了改进，使固体样品在1200k以下的热容数据可靠。采用光辐射交流量热技术，建立了一种测量1升液体样品热容的微量热计。研制了一种微弹量热计，它只需要10毫克的样品就可以测定无机和有机化合物的燃烧焓。对微溶液量热仪进行了改进，使苯与过二苯的混合焓的测定精度达到1%。气相沉积样品的绝热微量热计为气相沉积非晶态材料的研究开辟了新的领域。它们表现出非线性的焓弛豫现象，其开始温度远低于液淬样品。带稀释制冷机的极低温量热计可以测定凝聚态物质的热容量，使其降至20mk。这澄清了磁性材料在成分之间具有弱相互作用的许多方面。这些发展扩大了量热实验对许多种类的新材料的适用性，而这些材料是可以少量制备的，这无疑打开了热科学新途径的大门。少

Many calorimetric methods owe their accurate data partly to large amount of purified speciman used in the experiments. Recent development in synthesis of new materials and characterization methods necessitated to miniaturize various types of calorimeters for the thermodynamic characterization. It is the purpose of this research project to aim at miniaturization of various kinds of reaction and non-reaction calorimeters for further development of thermoscience without loss of accuracy and precision of the resulting calorimetric data.A low-temperature adiabatic microcalorimeter was developed which made it possible to determine the third law entropy with small amount of specimen less than 1 g. A laser-flash calorimeter was improved so as to produce reliable heat capacity data of solid sample up to 1200 K. A microcalorimeter was built for measuring the heat capacity of a 1- l liquid sample using a light-irradiation ac calorimetric technique. A micro-bomb calorimeter was developed which req … More uired only 10 mg of sample for the determination of enthalpies of combustion of inorganic and organic compounds. A micro-solution calorimeter was improved in a sophisticated way so that the enthalpy of mixing between benzene and perdeuterobenzene was determined with inaccuracy of 1 %. An adiabatic micro-calorimeter for vapor-deposited sample clarified a new aspect of vapor-deposited amorphous material. They showed non-linear enthalpy relaxation phenomennon which started at much lower temperature than those for liquidd-quenched sample. A very low-temperature calorimeter with a dilution refrigerator made it possible to determine the heat capacity of condensed matter down to 20 mK. This clarified many aspects of magnetic material possessing weak interaction among the constituents.These development widen the applicability of the calorimetric experiments to many types of new materials which are possible to prepare only in small quantity, and surely open the door to novel way of thermoscience. Less