Dilatometric Measurement of the Thermal Expansion of Cobalt Single Crystal

The thermal expansion of an hexagonal cobalt single crystal has been measured in the temperature range between 77 and 900 K by using a comparative quartz dilatometer. The linear coefficients of the thermal expansions along the c and a axes are 17.8×10-6 and 12.5×10-6, respectively, at 300 K and increase with increasing temperature, their rates of increase being larger at low temperatures. The temperature variations of the volume expansion and the axial ratio c/a are also derived from those of the thermal expansions.