Cerium 4f electronic spin dynamics in single crystals of the heavy-fermion system CeFePO is studied by means of ac-susceptibility, specific heat and muon-spin relaxation (μSR). Short-range static magnetism occurs below the freezing temperature Tg ~ 0.7 K, which prevents the system from accessing the putative ferromagnetic quantum critical point. In the μSR, the sample-averaged muon asymmetry function is dominated by strongly inhomogeneous spin fluctuations below 10 K and exhibits a characteristic time-field scaling relation expected from glassy spin dynamics, strongly evidencing cooperative and critical spin fluctuations. The overall behavior can be ascribed neither to canonical spin glasses nor other disorder-driven mechanisms.
@article{arxiv.1210.5463,
title = {Avoided ferromagnetic quantum critical point: Unusual short-range ordered state in CeFePO},
author = {S. Lausberg and J. Spehling and A. Steppke and A. Jesche and H. Luetkens and A. Amato and C. Baines and C. Krellner and M. Brando and C. Geibel and H. -H. Klauss and F. Steglich},
journal= {arXiv preprint arXiv:1210.5463},
year = {2015}
}
Comments
5 pages, 4 figures, accepted for publication in Physical Review Letters, Link: http://prl.aps.org/accepted/6207bYdaGef1483c419928305372ce2d4419eb96f