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TT: Fachverband Tiefe Temperaturen
TT 27: Correlated Electrons: Other Materials
TT 27.10: Vortrag
Dienstag, 19. März 2024, 12:00–12:15, H 3010
31 P NMR studies of quasi-two-dimensional magnetic correlations in A CrP 2 S 6 ( A = Cu, Ag) — •Saramgi Chencheriparambil Sivan1, 2, Ranjith Kumar Kizhake Malayil1, Lukas Prager1, Saicharan Aswartham1, Bernd Büchner1, 2, and Hans-Joachim Grafe1 — 1Leibniz IFW Dresden, D-01069 — 2Institute for Solid State and Materials Physics, TU Dresden, D-01069
The AA ’P 2 S 6 ( A , A ’ = transition metal ions) family of quasi-two-dimensional van der Waals materials has proven to be a model system for low-dimensional magnetism. These materials provide an ideal platform to study the Hamiltonians of fundamental magnetism models, including the Ising, XY, and Heisenberg models. Here we present detailed 31 P NMR measurements on single-crystal samples of A CrP 2 S 6 . The high-temperature single narrow NMR line shows a splitting at about 160 K for CuCrP 2 S 6 , which is due to the antiferroelectric transition, while a pake−doublet NMR spectrum is observed for AgCrP 2 S 6 at room temperature. In CuCrP 2 S 6 , 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 CuCrP 2 S 6 shows a sharp peak due to the critical fluctuations. The temperature dependence of (T1T)−1 shows a broad maximum at about 60 K and a critical enhancement at TN . TN are anisotropic near the critical regime. AgCrP 2 S 6 exhibits AFM order at 20 K, as evidenced by the clear splitting of the NMR spectra and the divergence of T1−1 (T) at TN . In contrast to CuCrP 2 S 6 , the temperature dependence of (T1T)−1 shows only a critical enhancement around TN without a broad anomaly.
Keywords: Nuclear Spin Resonance; van der Waals materials; Magnetic anisotropy; Spin correlation; 2D Magnetism