Construction of relaxation calorimetry for 101–2 μg samples and heat capacity measurements of organic complexes
Construction of relaxation calorimetry for 101–2 μg samples and heat capacity measurements of organic complexes
复制标题
101–2 μg 样品的弛豫量热法的构建和有机复合物的热容测量
DOI：
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复制
发表时间：
2016
影响因子：
4.4
通讯作者：
Y. Nakazawa
中科院分区：
文献类型：
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作者：
S. Imajo;S. Fukuoka;S. Yamashita;Y. Nakazawa
摘要
Abstract
We report design and constructional details of a small-sized sample stage for relaxation calorimetry by utilizing commercially available ruthenium oxide chip sensors. The reduction in addenda heat capacity attained by fabrication of chip sensors made it possible to measure absolute values of the heat capacity of molecular compounds weighing in an order of 101–2 μg with better temperature resolution. The result of calibration of the system by measuring 54.0 μg metal indium which shows superconductive transition at 3.2 K is presented in the former part. Upon determining thermodynamic parameters of γ and β corresponding to the electronic heat capacity coefficient and the lattice heat capacity coefficient, respectively, we confirm that accurate measurements by such small amount of sample are possible. The magnitude of heat capacity jump is also discussed by comparing 0 T data and those under magnetic fields. Using this new calorimetry system, we then measured heat capacity of κ-type organic superconductive salts of κ-(BEDT-TTF)2Cu(NCS)2 and κ-(BEDT-TTF)2Cu[N(CN)2]Br down to 0.7 K and discuss the nodal feature of the superconductive gap in them in the latter part. Measurements down to 3He temperature region with external magnetic fields will be possible for various organic conducting systems by a single piece of a crystal.