Berlin 2018 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 89: Disordered Quantum Systems
TT 89.1: Vortrag
Donnerstag, 15. März 2018, 11:30–11:45, HFT-FT 131
Spin freezing and spin dynamics in the reentrant spin glass FexCr1−x — •Georg Benka1, Steffen Säubert1,2, Philipp Schmakat2,3, Andreas Bauer1, Stephen M. Shapiro4, Peter Böni3, and Christian Pfleiderer1 — 1Lehrstuhl für Topologie korrelierter Systeme, Technische Universität München, Garching, Germany — 2Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Garching, Germany — 3Lehrstuhl für Neutronenstreuung, Technische Universität München, Garching, Germany — 4Brookhaven National Laboratory, Department of Physics, Upton, USA
FexCr100−x shows reentrant spin glass behaviour below a concentration dependent freezing temperature Tf. In contrast to a classical spin glass, the ground state changes from antiferromagnetic to ferromagnetic order with increasing iron concentration x. For intermediate concentrations a coexistence of the spin glass and magnetic order is discussed [1, 2].
We present a comprehensive study of the FexCr100−x system over a wide range of concentrations by means of magnetisation measurements in combination with neutron depolarisation and neutron spin echo methods.
This allows us to compare the relaxation process depending on the particular state at high temperatures. Our measurements provide an unprecedented combination of microscopic information on the spin dynamics and spin freezing on multiple length and time scales.
S. K. Burke et al., J. Phys. F: Met. Phys. 13 (1983) 451
S. M. Shapiro et al., Phys. Rev. B 24 (1981) 6661