Berlin 2015 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 71: Correlated Electrons: Poster Session
TT 71.38: Poster
Mittwoch, 18. März 2015, 15:00–18:00, Poster B
Amorphous ferromagnetism and re-entrant magnetic glassiness in Sm2Mo2O7 — •Giacomo Prando1, Pietro Carretta2, Anja Wolter-Giraud1, Romuald Saint-Martin3, Alexandre Revcolevschi3, and Bernd Büchner1,4 — 1Leibniz-Institut für Festkörper- und Werkstoffforschung (IFW) Dresden, D-01171 Dresden, Germany — 2Dipartimento di Fisica e Unitá CNISM di Pavia, Universitá di Pavia, I-27100 Pavia, Italia — 3Laboratoire de Physico-Chimie de l’Etat Solide, ICMMO, UMR8182, Université Paris-Sud, F-91405 Orsay, France — 4Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden, Germany
We report on the investigation of a high-quality single crystal of Sm2Mo2O7 by means of dc magnetometry, muon spin spectroscopy and high-harmonics ac susceptibility [1]. The magnetic phase of the Mo4+ sublattice develops below TC = 78 K and is typically discussed in the literature as a conventional itinerant ferromagnetic state. However, our results clearly detect a complicated superposition of conventional and highly disordered magnetic behaviors below 78 K sharing several common features with amorphous ferromagnetic alloys and with other insulating spin-glass pyrochlore molybdates. As typical for amorphous ferromagnets, a freezing of the transverse XY spin components of Mo4+ below T ∼ 25 K is evidenced, an effect otherwise known as re-entrant spin-glass phase. Our results shed new light on the magnetic properties of Sm2Mo2O7 and on the overall electronic phase diagram commonly accepted for pyrochlore molybdates.
[1] G. Prando et al., Phys. Rev. B 90, 085111 (2014)