2024/08/12 by Sunil Yadav, Yadav, S., Salomé Delgado +21
Chemistry · Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Chemistry #Condensed matter physics #Crystal Structures and Properties #Crystallography #FOS: Physical sciences #Inorganic Fluorides and Related Compounds #Materials Science (cond-mat.mtrl-sci) #Materials science #Nuclear magnetic resonance #Physics #Spins #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2408.06284
published in arXiv (Cornell University) (Cornell University)
openalex publication_date 2024/08/12 · openalex created_date 2024/09/11 · openalex updated_date 2026/08/06
We report results of magnetization and 19F NMR measurements in the normal state of as-grown LaO0.5F0.5BiS2. The magnetization is dominated by a temperature-independent diamagnetic component and a field- and temperature-dependent paramagnetic contribution Mμ(H,T) from a ∼1000~ppm concentration of local moments, an order of magnitude higher than can be accounted for by measured rare-earth impurity concentrations. Mμ(H,T) can be fit by the Brillouin function BJ(x) or, perhaps more realistically, a two-level \tanh(x) model for magnetic Bi 6p ions in defect crystal fields. Both fits require a phenomenological Curie-Weiss argument x = μeffH/(T + TW), TW ≈ 1.7 K. There is no evidence for magnetic order down to 2 K, and the origin of TW is not clear. 19F frequency shifts, linewidths, and spin-lattice relaxation rates are consistent with purely dipolar 19F/defect-spin interactions. The defect-spin correlation time τc(T) obtained from 19F spin-lattice relaxation rates obeys the Korringa relation τcT = const., indicating the relaxation is dominated by conduction-band fluctuations.