Pseudo-easy-axis anisotropy in antiferromagnetic S=1 diamond-lattice systems

Vaidya, S.; Hernández-Melián, A.; Tidey, J. P.; Curley, S. P. M.; Sharma, S.; Manuel, P.; Wang, C.; Hannaford, G. L.; Blundell, S. J.; Manson, Z. E.; Manson, J. L.; Singleton, J.; Lancaster, T.; Johnson, R. D.; Goddard, P. A.

Abstract

We investigate the magnetic properties of S = 1 antiferromagnetic diamond-lattice, NiX2(pyrimidine)2 (X = Cl, Br), hosting a single-ion anisotropy (SIA) orientation which alternates between neighboring sites. Through neutron diffraction measurements of the X = Cl compound, the ordered state spins are found to align collinearly along a pseduo-easy axis, a unique direction created by the intersection of two easy planes. Similarities in the magnetization, exhibiting spin-flop transitions, and the magnetic susceptibility in the two compounds imply that the same magnetic structure and a pseduo-easy axis is also present for X = Br. We estimate the Hamiltonian parameters by combining analytical calculations and Monte Carlo (MC) simulations of the spin-flop and saturation field. The MC simulations also reveal that the spin-flop transition occurs when the applied field is parallel to the pseduo-easy axis. Contrary to conventional easy-axis systems, there exist field directions perpendicular to the pseduo-easy axis for which the magnetic saturation is approached asymptotically and no symmetry-breaking phase transition is observed at finite fields.

Citation

Vaidya, S., Hernández-Melián, A., Tidey, J. P., Curley, S. P. M., Sharma, S., Manuel, P., Wang, C., Hannaford, G. L., Blundell, S. J., Manson, Z. E., Manson, J. L., Singleton, J., Lancaster, T., Johnson, R. D., & Goddard, P. A. (2024). Pseudo-easy-axis anisotropy in antiferromagnetic S=1 diamond-lattice systems. Physical Review B, 110(17), https://doi.org/10.1103/physrevb.110.174438

• Journal Article Type: Article
• Acceptance Date: Oct 24, 2024
• Online Publication Date: Nov 21, 2024
• Publication Date: Nov 21, 2024
• Deposit Date: Jan 20, 2025
• Publicly Available Date: Jan 20, 2025
• Journal: Physical Review B
• Print ISSN: 2469-9950
• Electronic ISSN: 2469-9969
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 110
• Issue: 17
• DOI: https://doi.org/10.1103/physrevb.110.174438
• Public URL: https://durham-repository.worktribe.com/output/3343055