The carrier contribution to the specific heat coefficient, Ce/T, of Sr1-xKxFe2As2 with 0≤x≤1 has been determined. The Ce/T at the optimal doping level appears to be T-independent above the superconducting transition temperature Tc. Systematic reductions and increases with cooling below 100 K, on the other hand, characterize the underdoped and overdoped samples, respectively. As the result, the low-T limit of the normal-state Ce/T increases almost linearly with x by a factor of 3 over 0 ≤x≤1. However, the Ce/T suppression across the magnetostructure transition of the underdoped samples is actually negligibly small. In particular, the extracted γH- γL at x=0, which should include all suppression effects, is comparable to or even smaller than that of x=0.15, where γH and γL are the high- and low-T limits of the normal-state C e/T. Therefore, it appears that, while the magnetostructure transition still plays a role, it may not be the main factor behind the C e/T evolution.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2011 Jan 19|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics