Funding
EMP is funded through the Horizon2020 programme of the European Commission.
Selected Publications
 

Specific Heat of K0.71Na0.29Fe2As2 at Very Low Temperatures

A. Reifenberger, M. Hempel, P. Vogt, S. Aswartham, M. Abdel-Hafiez, V. Grinenko, S. Wurmehl, S.-L. Drechsler, A. Fleischmann, C. Enss and R. Klingeler

A commercially available calorimeter has been used to investigate the specific heat of a high-quality K0.71Na0.29Fe2As2single crystal.The addenda heat capacity of the calorimeter is determined in the temperature range 0.02K ≤ T ≤ 0.54K. The
data of the K0.71Na0.29Fe2As2 crystal imply the presence of a large T2 contribution to the specific heat which gives evidence of d-wave order parameter symmetry in the superconducting state. To improve the measurements, a novel design for a calorimeter
with a paramagnetic temperature sensor is presented. It promises a temperature resolution of ΔT ≈ 0.1μK and an addenda heat capacity less than 200 pJ/K at T < 100mK.


Journal of Low Temperature Physics 175, 755-763 (2014)

doi: 10.1007/s10909-014-1168-7