Baker, P. J., Giblin, Sean  ORCID: https://orcid.org/0000-0003-1876-8619, Pratt, F. L., Liu, R. H., Wu, G., Chen, X. H., Pitcher, M. J., Parker, D. R., Clarke, S. J. and Blundell, S. J.
2009.
Heat capacity measurements on FeAs-based compounds: a thermodynamic probe of electronic and magnetic states.
New Journal of Physics
11
, 025010.
10.1088/1367-2630/11/2/025010
|
Abstract
We report heat capacity measurements of the pnictide materials SmFeAsO1-xFx, NdFeAsO, LaFeAsO1-xFx and LiFeAs. For SmFeAsO1- xFx, with x close to 0.1, we use 3He measurements to demonstrate a transfer of entropy from the peak at TN to a previously unidentified ~2 K feature, which grows with increasing doping. Our results on the Sm samples are compared with a similarly doped La sample to elucidate the crystal field levels of the Sm3+ ion at 0, 20 and 45 meV, which lead to a Schottky-like anomaly, and also show that there is a significant increase in the Sommerfeld coefficient γ when La is replaced by Sm or Nd. The lattice contribution to the heat capacity of the superconducting oxypnictides is found to vary negligibly with chemical substitution. We also present a heat capacity measurement of LiFeAs showing the feature at Tc, which is significantly rounded and much smaller than the BCS value.
| Item Type: | Article |
|---|---|
| Date Type: | Publication |
| Status: | Published |
| Schools: | Schools > Physics and Astronomy |
| Subjects: | Q Science > QC Physics |
| Publisher: | IOP Publishing |
| ISSN: | 1367-2630 |
| Last Modified: | 21 Oct 2022 10:50 |
| URI: | https://orca.cardiff.ac.uk/id/eprint/41501 |
Citation Data
Cited 34 times in Scopus. View in Scopus. Powered By Scopus® Data
Actions (repository staff only)
 |
Edit Item |
Altmetric
Altmetric