Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 55: Graphene and 2D Materials (joint session TT/HL)
HL 55.13: Vortrag
Donnerstag, 20. März 2025, 18:15–18:30, H33
31P NMR studies of quasi-two-dimensional (2D) magnetic correlations in ACrP2S6 (A= Cu, Ag) — •Saramgi Sivan1,2, Kizhake Malayil Ranjith1, Lukas Prager1,2, Saicharan Aswartham1, Bernd Büchner1,2, and Hans-Joachim Grafe1 — 1Leibniz IFW Dresden, D-01069 — 2Institute for Solid State and Materials Physics, TU Dresden, D-01062
The AA′P2S6 (A, A′ = transition metal ions) family of quasi-2D van der Waals materials has proven to be a model system for low-dimensional magnetism. Here we present detailed 31P NMR measurements on the single crystals of ACrP2S6. The high-temperature single narrow NMR line shows a splitting at about 160 K for CuCrP2S6, which is attributed to the antiferroelectric (AFE) transition, while a pake-doublet NMR spectrum is observed for AgCrP2S6 at room temperature, but no AFE transition at lower temperatures. In CuCrP2S6, we observed further line splitting below 30 K, reflecting the antiferromagnetic (AFM) order. At TN = 30 K, the NMR spin-lattice relaxation rate T1−1(T) in CuCrP2S6 measured at 2.5 T shows a sharp peak due to the critical fluctuations. The TN is suppressed towards lower temperatures when measured at higher magnetic fields. The (T1T)−1(T) measured at 7 T shows a broad maximum at about 60 K and a critical enhancement at TN. On the other hand, AgCrP2S6 exhibits in-plane AFM order at 20 K, as evidenced by the clear splitting of the NMR spectra, the divergence of T1−1(T) at TN, and a broad maximum in the NMR Knight shift. In contrast to CuCrP2S6, the (T1T)−1 (T) shows only a critical enhancement around TN without a broad anomaly.
Keywords: Nuclear magnetic resonance; Van der Waals systems; Low-dimensional magnetism; Spin dynamics; Antiferromagnetism