Temperature dependent lattice constant of InSb above room temperature

Using temperature dependent X-ray diffraction on two InSb single crystalline substrates, the bulk lattice constant of InSb was determined between 32 and 325 °C. A polynomial function was fitted to the data: a ( T ) = 6.4791 + 3.28 × 10 − 5 × T + 1.02 × 10 − 8 × T 2 A ( T in °C), which gives slightly higher values than previously published (which go up to 62 °C). From the fit, the thermal expansion of InSb was calculated to be α ( T ) = 5.062 × 10 − 6 + 3.15 × 10 − 9 × T K − 1 ( T in °C). We found that the thermal expansion coefficient is higher than previously published values above 100 °C (more than 10% higher at 325 °C).