Low- and high-temperature heat capacity of metallic technetium

Abstract

The heat capacity of technetium metal has been measured from 2.1 K to 293 K using relaxation calorimetry and the enthalpy increment up to 1700 K using drop calorimetry. The low-temperature calorimetry measurements revealed a superconducting transition temperature of T_C = (7.76 ± 0.08) K. The zero-degree Debye temperature(θ_E) and the electronic heat capacity coefficient (γ_e) of the normal state were derived as (307 ± 5) K and (4.22 ± 0.20) mJ·K⁻²·mol⁻¹, respectively. The standard entropy of the superconducting standard state was derived as S_m^° (298.15) = (36.8 ± 1.3) J·K⁻¹·mol⁻¹. The fitting of enthalpy-increment data together with high-temperature heat capacity data reported in literature yielded a heat capacity equation up to 1700 K.