Heat capacity measurements were performed on recently discovered iron based layered superconductors, non doped LaFePO and fluorine doped LaFePO. A relatively large electronic heat capacity coefficient and a small normalized heat capacity jump at Tc = 3.3 K were observed in LaFePO. LaFePO0.94F0.06 had a smaller electronic heat capacity coefficient and a larger normalized heat capacity jump at Tc = 5.8 K. These values indicate that these compounds have strong electron electron correlation and magnetic spin fluctuation, which are the signatures of unconventional superconductivity mediated by spin fluctuation.
@article{arxiv.0806.3139,
title = {Possible unconventional superconductivity in iron-based layered compound LaFePO: Study of heat capacity},
author = {Yoshimitsu Kohama and Yoichi Kamihara and Hitoshi Kawaji and Tooru Atake and Masahiro Hirano and Hideo Hosono},
journal= {arXiv preprint arXiv:0806.3139},
year = {2008}
}