Description of the parallel thermal conductance technique for the measurement of the thermal conductivity of small diameter samples

In order to measure the thermal conductivity of small needlelike samples (2 .0x0.05x0.1 mm(3)) such as pentatellurides and single carbon fibers, we hav e developed a new technique called the parallel thermal conductance (PTC) t echnique. In the more typical steady state method that is used for measurin g thermal conductivity, thermocouples are attached to the sample in order t o measure the temperature gradient and a heater in order to supply this gra dient. However, attaching thermocouples and heaters directly to small sampl es may be relatively difficult, and cause large heat losses and errors. Thu s, the measurement of the thermal conductivity of small samples and thin fi lms has been a formidable challenge, with only few successes, due, among ot her factors, to the heat loss. It is also difficult for the small samples t o support the heaters and thermocouples without causing damage to the sampl e. In this paper we describe the recently developed PTC method providing me asurements on standards as well as single carbon fibers, in addition to pre liminary pentatelluride crystals measurements. (C) 2001 American Institute of Physics.