Extremely well isolated two-dimensional spin-1/2 antiferromagnetic Heisenberg layers with a small exchange coupling in the molecular-based magnet CuPOF

Opherden, D.; Nizar, N.; Richardson, K.; Monroe, J.C.; Turnbull, M.M.; Polson, M.; Vela, S.; Blackmore, W.J.A.; Goddard, P.A.; Singleton, J.; Choi, E.S.; Xiao, F.; Williams, R.C.; Lancaster, T.; Pratt, F.L.; Blundell, S.J.; Skourski, Y.; Uhlarz, M.; Ponomaryov, A.N.; Zvyagin, S.A.; Wosnitza, J.; Baenitz, M.; Heinmaa, I.; Stern, R.; Kühne, H.; Landee, C.P.

doi:10.1103/physrevb.102.064431

Extremely well isolated two-dimensional spin-1/2 antiferromagnetic Heisenberg layers with a small exchange coupling in the molecular-based magnet CuPOF

Opherden, D.; Nizar, N.; Richardson, K.; Monroe, J.C.; Turnbull, M.M.; Polson, M.; Vela, S.; Blackmore, W.J.A.; Goddard, P.A.; Singleton, J.; Choi, E.S.; Xiao, F.; Williams, R.C.; Lancaster, T.; Pratt, F.L.; Blundell, S.J.; Skourski, Y.; Uhlarz, M.; Ponomaryov, A.N.; Zvyagin, S.A.; Wosnitza, J.; Baenitz, M.; Heinmaa, I.; Stern, R.; Kühne, H.; Landee, C.P.

Authors

D. Opherden

N. Nizar

K. Richardson

J.C. Monroe

M.M. Turnbull

M. Polson

S. Vela

W.J.A. Blackmore

P.A. Goddard

J. Singleton

E.S. Choi

F. Xiao

R.C. Williams

Professor Tom Lancaster tom.lancaster@durham.ac.uk
Professor

F.L. Pratt

S.J. Blundell

Y. Skourski

M. Uhlarz

A.N. Ponomaryov

S.A. Zvyagin

J. Wosnitza

M. Baenitz

I. Heinmaa

R. Stern

H. Kühne

C.P. Landee

Abstract

We report on a comprehensive characterization of the newly synthesized Cu2+-based molecular magnet [Cu(pz)2 (2-HOpy)2](PF6 )2 (CuPOF), where pz = C4H4N2 and 2-HOpy = C5H4NHO. From a comparison of theoretical modeling to results of bulk magnetometry, specific heat, μ+SR, ESR, and NMR spectroscopy, this material is determined as an excellent realization of the two dimensional square-lattice S = 1 2 antiferromagnetic Heisenberg model with a moderate intraplane nearest-neighbor exchange coupling of J/kB = 6.80(5) K, and an extremely small interlayer interaction of about 1 mK. At zero field, the bulk magnetometry reveals a temperature-driven crossover of spin correlations from isotropic to XY type, caused by the presence of a weak intrinsic easy-plane anisotropy. A transition to long-range order, driven by the low-temperature XY anisotropy under the influence of the interlayer coupling, occurs at TN = 1.38(2) K, as revealed by μ+SR. In applied magnetic fields, our 1H-NMR data reveal a strong increase of the magnetic anisotropy, manifested by a pronounced enhancement of the transition temperature to commensurate long-range order at TN = 2.8 K and 7 T.

Citation

Opherden, D., Nizar, N., Richardson, K., Monroe, J., Turnbull, M., Polson, M., …Landee, C. (2020). Extremely well isolated two-dimensional spin-1/2 antiferromagnetic Heisenberg layers with a small exchange coupling in the molecular-based magnet CuPOF. Physical Review B, 102(6), Article 064431. https://doi.org/10.1103/physrevb.102.064431

Journal Article Type	Article
Acceptance Date	Jul 27, 2020
Online Publication Date	Aug 28, 2020
Publication Date	2020-08
Deposit Date	Aug 31, 2020
Publicly Available Date	Sep 1, 2020
Journal	Physical Review B
Print ISSN	2469-9950
Electronic ISSN	2469-9969
Publisher	American Physical Society
Peer Reviewed	Peer Reviewed
Volume	102
Issue	6
Article Number	064431
DOI	https://doi.org/10.1103/physrevb.102.064431
Related Public URLs	https://arxiv.org/abs/2005.12058

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