We report on results of electrical resistivity and structural investigations on the cubic modification of FeGe under high pressure. The long-wavelength helical order (TC=280 K) is suppressed at a critical pressure pc≈19 GPa. An anomaly in the resistivity data at TX(p) and strong deviations from a Fermi-liquid behavior in a wide pressure range above pc suggest that the suppression of TC disagrees with the standard notion of a quantum critical phase transition. The metallic ground state persisting at high pressure can be described by band-structure calculations if structural disorder due to zero-point motion is included. Discontinuous changes in the pressure dependence of the shortest Fe-Ge interatomic distance occurring close to the TC(p) phase line could be interpreted as a symmetry-conserving transition of first order.
@article{arxiv.cond-mat/0606493,
title = {Metallic State in Cubic FeGe beyond its Quantum Phase Transition},
author = {P. Pedrazzini and H. Wilhelm and D. Jaccard and T. Jarlborg and M. Schmidt and M. Hanfland and L. Akselrud and H. Q. Yuan and U. Schwarz and Yu. Grin and F. Steglich},
journal= {arXiv preprint arXiv:cond-mat/0606493},
year = {2007}
}