Unconventional superconductivity in the layered iron germanide YFe$_2$Ge$_2$
Abstract
Since the discovery of superconductivity in LaFePO in 2006, numerous iron-based superconductors have been identified within diverse structure families, all of which combine iron with a group-V (pnictogen) or group-VI (chalco- gen) element. Unconventional superconductivity is extremely rare among transition metal compounds outside these layered iron systems and the cuprates, and it is almost universally associated with highly anisotropic electronic properties and nearly 2D Fermi surface geometries. The iron-based intermetallic YFeGe features a 3D Fermi surface and a strongly enhanced low temperature heat capacity, which signals strong electronic correlations. We present data from a new generation of high quality samples of YFeGe, which show superconducting transition anomalies below 1.8 K in thermodynamic as well as transport measurements, establishing that superconductivity is intrinsic in this layered iron compound outside the known superconducting iron pnictide or chalcogenide families. The Fermi surface geometry of YFeGe resembles that of KFeAs in the high pressure collapsed tetragonal phase, in which superconductivity at temperatures as high as 10 K has recently been reported, suggesting an underlying connection between the two systems.
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Cite
@article{arxiv.1507.01436,
title = {Unconventional superconductivity in the layered iron germanide YFe$_2$Ge$_2$},
author = {Jiasheng Chen and Konstantin Semeniuk and Zhuo Feng and Pascal Reiss and Yang Zou and Peter W. Logg and Giulio I. Lampronti and F. Malte Grosche},
journal= {arXiv preprint arXiv:1507.01436},
year = {2016}
}