Superconductivity and Physical Properties of CaPd₂Ge₂ Single Crystals
We present the superconducting and normal state properties of CaPd2Ge2single crystals investigated by magnetic susceptibility χ, isothermal magnetization M, heat capacity Cp, in-plane electrical resistivity ρ and London penetration depth λ versus temperature T and magnetic field H measurements. Bulk superconductivity is inferred from the ρ(T) and Cp(T) data. The ρ(T) data exhibit metallic behavior and a superconducting transition with Tc onset = 1.98K and zero resistivity at Tc 0 = 1.67 K. The χ(T) reveals the onset of superconductivity at 2.0K. For T > 2.0 K, the χ(T) and M(H) are weakly anisotropic paramagnetic with χab > χc. The Cp(T) data confirm the bulk superconductivity below Tc = 1.69(3) K. The superconducting state electronic heat capacity is analyzed within the framework of a single-band α-model of BCS superconductivity and various normal and superconducting state parameters are estimated. Within the α-model, the Cp(T) data and the ab plane λ(T) data consistently indicate a moderately anisotropic s-wave gap with Δ(0)/kBTc ≈ 1.6, somewhat smaller than the BCS value of 1.764. The relationship of the heat capacity jump at Tc and the penetration depth measurement to the anisotropy in the s-wave gap is discussed.
V. K. Anand et al., "Superconductivity and Physical Properties of CaPd₂Ge₂ Single Crystals," Journal of Physics Condensed Matter, vol. 26, no. 40, article no. 405702, IOP Publishing, Oct 2014.
The definitive version is available at https://doi.org/10.1088/0953-8984/26/40/405702
Keywords and Phrases
Anisotropic Gap; Penetration Depth; Pnictides; Superconductivity
International Standard Serial Number (ISSN)
Article - Journal
© 2014 IOP Publishing, All rights reserved.
08 Oct 2014