Regensburg 2016 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 78: Correlated Electrons: Poster Session
TT 78.22: Poster
Donnerstag, 10. März 2016, 15:00–18:30, Poster D
NMR of the frustrated spin-ladder system copper-sulfolane — •D. Dmytriieva1, Z. Zhang1, M. Naumann1, H. Kühne1, J. Wosnitza1, E. Wulf2, and A. Zheludev2 — 1Hochfeld-Magnetlabor Dresden (HLD), Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany — 2Neutron Scattering and Magnetism, Laboratory for Solid State Physics, ETH Zürich, Switzerland
We present first results from NMR experiments on the frustrated spin-ladder compound H8C4SO2·Cu2Cl4 (copper-sulfolane). From a comparison of the 35Cl NMR spectra to macroscopic susceptibility data, we demonstrate that the 35Cl nuclei are suitable local probes for the magnetic correlations of the nearby Cu2+ S=1/2 moments. At magnetic fields exceeding 3.75 T and temperatures approaching 1.6 K, we find an increase of the nuclear spin-lattice relaxation rate, signaling the onset of long-range magnetic order. For the structurally disordered version of this compound, specific-heat measurements indicate a strong suppression of the magnetic ordering temperature with surprisingly small concentrations of bromine substitution on the non-magnetic halogen site. It has been proposed that this phenomenology is driven by a novel mechanism, based on random frustration by bond disorder. In an approach to shed light on the substitution-induced modification of exchange couplings and correlations in the vicinity of the bromine sites as well as on the slow, long-range magnetic fluctuations at the transition to the ordered state, we show first results of 35Cl and 81Br NMR data obtained from high-quality single crystals.