Magnetic properties of a classical XY spin dimer in a planar magnetic field

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:416

Article

Ciftja, Orion¹  Prenga, Dode² 

[1] Prairie View A&M Univ, Dept Phys, Prairie View, TX 77446 USA

[2] Univ Tirana, Fac Nat Sci, Dept Phys, Blvd Zog 1, Tirana, Albania

关键词: Molecular magnetism;    Heisenberg spins;    XY model;   

DOI  :  10.1016/j.jmmm.2016.04.070

来源: Elsevier

【 摘 要 】

Single-molecule magnetism originates from the strong intra-molecular magnetic coupling of a small number of interacting spins. Such spins generally interact very weakly with the neighboring spins in the other molecules of the compound, therefore, inter-molecular spin couplings are negligible. In certain cases the number of magnetically coupled spins is as small as a dimer, a system that can be considered the smallest nanomagnet capable of storing non-trivial magnetic information on the molecular level. Additional interesting patterns arise if the spin motion is confined to a two-dimensional space. In such a scenario, clusters consisting of spins with large-spin values are particularly attractive since their magnetic interactions can be described well in terms of classical Heisenberg XY spins. In this work we calculate exactly the magnetic properties of a nanomagnetic dimer of classical XY spins in a planar' external magnetic field. The problem is solved by employing a mathematical approach whose idea is the introduction of auxiliary spin variables into the starting expression of the partition function. Results for the total internal energy, total magnetic moment, spin-spin correlation function and zero-field magnetic susceptibility can serve as a basis to understand the magnetic properties of large-spin dimer building blocks. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

Free