3. Development of the Novel Measuring Technique for Thermal Properties

　 In the field of low temperature physics and cryogenic engineering, the thermal properties of the materials (thermal conductivity k, thermal diffusivity a, specific heat C, thermolelctric power S, thermal expansion dL/L) are the important and valuable parameters for the fundamental research and the practical applications. In our laboratory, the fully automated measuring system of these thermal properties was constructed at the temperature range of 4~300 K and at the magnetic field of 0~10T. In this system, a Gifford-McMahon (GM) cycle helium refrigerator was used as the cryostat. The magnetic field of up to 10 T was applied using a cryocooler-cooled superconducting magnet.

　 A new experimental setup and analysis method for simultaneous determination of the anisotropic thermal conductivities (k_x, k_y) was also proposed for materials with uniaxial anisotropy or a layer-like structure. Furthermore, we proposed the measuring method of the thermal contact resistivity (W_c) through the connection between two materials. In this way, the development of new measuring method for the thermal properties was also planned.

《Issues》

・Thermal Conductivity Measurement
・Thermal Diffusivity Measurement
・Apparatus under the Magnetic Field
・Thermal contact resistivity Measurment
・Simultaneous determination of the anisotropic thermal conductivities