Thermal expansion and Grüneisen parameters of InBi

Abstract

Thermal expansion of InBi single crystals was measured over the temperature range 4.2−350 °K by dilatometry and x−ray diffraction. Unusually high anisotropy was observed; upon cooling, the samples expand in the c direction and contract perpendicular to c. α∥ is an order of magnitude more negative than the negative thermal expansion coefficients noted for other materials. The 300 °K thermal expansion coefficients (α⊥=60±5×10−6/ °K, α∥=−86±5×10−6/ °K) were used to calculate the following Grüneisen parameters for room temperature: γ∥=0.5±0.1, γ⊥ =1.5±0.2, and γ=0.7±0.1.