Thermal diffusivities of group V semimetals

A flash method, employing a pulsed flashlamp-pumped dye laser has been used to determine the thermal diffusivities of elemental arsenic, antimony, and bismuth. Measurements were made both on poly-crystalline samples and on oriented single crystal (111) wafers in the form of small disks 3.0?7.0 mm in diameter, and 0.43–1.33 mm thick. Thermocouples (0.076 mm dia) monitor the back surface temperature as a function of time after the front of the sample is exposed to a single laser pulse of pulse width (τ) <1.0 μsec. The room temperature thermal diffusivities α (cm²/sec) of polycrystalline As, Sb and Bi are respectively: 0.234, 0.182 and 0.0651. The diffusivities parallel to the trigonal crystal axis α₁ are: 0.119,0.142 and 0.0350. Measurements on polycrystalline Cu, Al and Ti yield 1.13, 0.96 and 0.085 cm²/sec, in agreement with literature values.