Abstract

In the present paper, a study of the magnetic properties of a spin-1/2 Ising–Heisenberg Cairo pentagonal structure is presented. The model has been investigated in [F.C. Rodrigues, S.M. de Souza, O. Rojas, Ann. Phys. 379, 1 (2017)] in the absence of external magnetic field. Here, we consider the effects of an external tunable magnetic field. By using the transfer matrix approach, we investigate the magnetic ground-state phase transition, the low-temperature magnetization process, and how the magnetic field influences the various thermodynamic parameters such as entropy, internal energy and specific heat. It is shown that the model exhibits intermediate magnetization plateaux accompanied by a double-peak in the specific heat curve versus temperature. The position of each magnetization jump is in accordance with the merging and/or separation of the two peaks in the specific heat curve. Considering different g-factors for the nodal Ising spins and spin dimers also results in arising different intermediate plateaux and to remarkable alterations of the thermodynamic properties of the model.

Graphical abstract

中文翻译：

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外部磁场作用下自旋1/2 Ising–Heisenberg开罗五边形模型：Landég因子的影响

摘要

在本文中，对自旋1/2 Ising–Heisenberg开罗五边形结构的磁性进行了研究。该模型已在[FC Rodrigues，SM de Souza，O. Rojas，Ann。物理 379，1（2017）]在没有外部磁场的情况下。在这里，我们考虑外部可调磁场的影响。通过使用传递矩阵方法，我们研究了磁性基态的相变，低温磁化过程，以及磁场如何影响各种热力学参数，例如熵，内能和比热。结果表明，该模型表现出中等的磁化平稳性，并伴随着比热曲线与温度的双峰。每个磁化跃变的位置根据比热曲线中两个峰的合并和/或分离。考虑不同的g节点Ising自旋和自旋二聚体的α-因子也会导致产生不同的中间平稳期，并导致模型热力学性质发生显着变化。

图形概要