Specific heat jump at the superconducting transition temperature in Ba(Fe(1-x)Cox)2As2 and Ba(Fe(1-x)Nix)2As2 single crystals

TL;DR

This study measures the specific heat jump at the superconducting transition in Ba(Fe(1-x)Cox)2As2 and Ba(Fe(1-x)Nix)2As2, revealing a scaling relationship with Tc over a wide range, indicating universal behavior.

Contribution

It provides detailed heat capacity data and demonstrates a universal scaling law for the specific heat jump across different iron-based superconductors.

Findings

Specific heat jump varies by a factor of ~10 across series.

Delta Cp/Tc scales as Tc^2 over two orders of magnitude.

Data from multiple compounds collapse onto a single log-log plot.

Abstract

We present detailed heat capacity measurements for Ba(Fe(1-x)Cox)2As2 and Ba(Fe(1-x)Nix)2As2 single crystals in the vicinity of the superconducting transitions. The specific heat jump at the superconducting transition temperature (Tc), Delta Cp/Tc, changes by a factor ~ 10 across these series. The Delta Cp/T$ vs. Tc data of this work (together with the literature data for Ba(Fe0.939Co0.061)2As2, (Ba0.55K0.45)Fe2As2, and (Ba0.6K0.4)Fe2As2) scale well to a single log-log plot over two orders of magnitude in Delta Cp/Tc and over about an order of magnitude in Tc, giving Delta Cp/Tc ~ Tc^2.