HTHP EA HomeIssue Contents

A new apparatus for thermal diffusivity and specific heat measurements of films and liquids by means of Fourier transform thermal analysis
Akikazu Maesono, Youichi Takasaki, Yukio Maeda, Ronald P Tye, Junko Morikawa, Toshimasa Hashimoto

A new apparatus based on the technique of Fourier transform thermal analysis for the measurement of thermal diffusivity, specific heat per unit volume, thermal effusivity, and thermal conductivity of thin solid and liquids films (of the order of micrometres) has been developed. The apparatus consists of the following components: specimen assembly; function synthesiser; DC potentiometer circuit; lock-in amplifier; DC microvoltmeter; temperature controller; computer; and special attachments. An electrically insulating specimen, 5 x 10 mm2 and 1 ~ 100 mm in thickness, is sandwiched between two gold layer resistors sputtered on two Pyrex glass plates, one being the heat generator and the other the sensor. For an electrically conductive specimen, a three-layered specimen stack, insulating film/conductive specimen/insulating film, can be used. By means of the Fourier transform technique, the thermal diffusivity across the specimen thickness can be obtained under heating or cooling at a constant rate of 0.2 ~ 10 K min-1 from -50 °C to 300 °C. By prior calibration measurements with a reference material of known properties, the specific heat per unit volume of the specimen film can be obtained simultaneously, so that the thermal conductivity and thermal effusivity can be derived. In addition, simultaneous measurement of thermal diffusivity, specific heat per unit volume, and thermal conductivity can be obtained during the melting process. Experiments illustrating various applications and measurements are described and discussed.

Full Text (IP)