Modeling molecular magnets with large exchange and on-site anisotropies

Article

关键词: SINGLE-CHAIN MAGNETS;    ION-ANISOTROPY;    NI-II;    BEHAVIOR;    MAGNETIZATION;    COMPLEXES;    BARRIER;    HEPTACYANOMOLYBDATE;    TEMPERATURE;    ORIGIN;   

DOI  :  10.1103/PhysRevB.98.214409

来源: SCIE

【 摘 要 】

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.

【 授权许可】

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