Modeling molecular magnets with large exchange and on-site anisotropies

Haldar, Sumit and Raghunathan, Rajamani and Sutter, Jean-Pascal and Ramasesha, S (2018) Modeling molecular magnets with large exchange and on-site anisotropies. In: PHYSICAL REVIEW B, 98 (21).

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Abstract

Spins in molecular magnets can experience both anisotropic exchange interactions and on-site magnetic anisotropy. In this paper, we study the effect of exchange anisotropy on the molecular magnetic anisotropy both with and without on-site anisotropy. When both the anisotropies are small, we find that the axial anisotropy parameter D-M in the effective spin Hamiltonian is the sum of the individual contributions due to exchange and on-site anisotropies. We find that even for axial anisotropy of about 15%, the low-energy spectrum does not correspond to a single-parent spin manifold but has intruder states arising from other parent spins. In this case, the low-energy spectrum cannot be described by multiplet states arising from a single approximate total spin state. We study the magnetic susceptibility, specific heat as a function of temperature, and magnetization as a function of applied field to characterize the system in this limit. We find that there is synergy between the two anisotropies, particularly for large systems with higher site spins.

Item Type:	Journal Article
Publication:	PHYSICAL REVIEW B
Publisher:	AMER PHYSICAL SOC
Additional Information:	Copyright of this article belongs to AMER PHYSICAL SOC
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	10 Feb 2019 09:39
Last Modified:	10 Feb 2019 09:39
URI:	http://eprints.iisc.ac.in/id/eprint/61359

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