Thermal Expansion at Low Temperatures

Abstract

CONSIDERABLE experimental data have been published¹ on the heat capacity C of solids, extending to temperatures which are very low in relation to their characteristic temperature θ data are available in the temperature region T ∼ θ/100, where the Debye continuum model may be expected to apply and where for metals the electronic contribution is important. Complementary information regarding the thermal expansion coefficient, α, is desirable as it would throw additional light on the lattice dynamics of solids, particularly the anharmonic nature² of the interatomic forces as evidenced by the Grüneisen parameter γ = 3αχV/C (χ = incompressibility, V = volume). Also any data obtained about an electronic expansion coefficient, α_e, in metals should provide useful information about their band structures