Berlin 2018 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 72: Poster Session: Correlated Electrons
TT 72.57: Poster
Mittwoch, 14. März 2018, 15:00–19:00, Poster B
ESR on the S=1/2 triangular magnet NaYbS2 — •Jörg Sichelschmidt1, Michael Baenitz1, Philipp Schlender2, and Thomas Doert2 — 1MPI for Chemical Physics of Solids, Dresden — 2TU Dresden, Dept. of Chemistry and Food Chemistry
NaYbS2 is one of a few spin 1/2 triangular quantum magnets for which a quantum spin-liquid picture is invoked. It has a delafossite structure with a planar triangular spin arrangement which leads to a low-temperature magnetism determined by exchange frustration effects. The crystal electric field (CEF) in NaYbS2 allows an effective spin S=1/2 in contrast to other delafossites materials which contain Cr3+ (S=3/2), for instance. There, extensive electron spin resonance (ESR) measurements of Cr3+ could verify a Z2 ordering scenario for triangular Heisenberg antiferromagnets [1].
We present first results of the Yb3+-ESR in single-crystalline NaYbS2. Well-defined spectra could be only observed for temperatures below ≈70 K because of the increasing influence of the relaxation via the higher CEF levels of Yb3+ towards higher temperatures.
The spectra show a large anisotropy, as determined by the CEF, similar to what has been observed in other Yb-systems [2]. Towards low temperatures we observed a moderate increase of the linewidth. This may indicate a spin-liquid state in agreement with NMR results where the increase of the spin-spin relaxation towards low temperatures is discussed as a signature of a quantum spin-liquid.
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A. Kutuzov et al., J. Phys. Cond. Mat. 20, 455208 (2008)