PdTe: a 4.5 K type-II BCS superconductor

Abstract

We report on the structure and physical properties of the polycrystalline PdTe superconductor, which is synthesized by the solid state reaction route via the quartz vacuum encapsulation technique at 750 °C. The as synthesized compound is crystallized in hexagonal crystal structure with P63/mmc space group. Both transport and magnetic measurements showed that PdTe is a bulk superconductor below 4.5 K. Isothermal magnetization (MH) and magneto-transport (R(T)H) measurements provided the values of the lower (Hc1) and upper (Hc2) critical fields as 250 Oe and 1200 Oe respectively at 2 K, establishing that the compound is clearly a type-II superconductor. The coherence length (ξ0) and Ginzburg–Landau parameter (κ) are estimated from the experimentally determined upper and lower critical fields, and are 449 Å and 1.48 respectively. Thermodynamic heat capacity measurements under different magnetic fields, i.e. Cp(T)H, showed a clear transition at 4.5 K (Tc), which shifts gradually to lower temperatures with application of field. The values of Debye temperature (ΘD) and electronic specific heat coefficient (γ) obtained from Cp(T) data are found to be 203 K and 6.01 mJ mol−1 K−2. The observed specific heat jump (ΔC/γTc) is 1.33, thus suggesting a possible weak coupling case for the PdTe superconductor.