发表机构
Erciyes University（埃尔齐耶斯大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究在 Bethe 晶格上构建混合自旋-1/2 与自旋-1 的铁磁双原子分子模型，通过平均场理论分析相图，发现多个铁磁相、重入行为及一二级相变，并考察了外磁场对磁化的影响。
AI 中文摘要
由自旋-1/2（$\sigma$）原子和自旋-1（$S$）原子组成的双原子分子被放置在配位数 $q=3, 4$ 或 6 的 Bethe 晶格（BL）的每个格点上。除了分子内单个原子之间的铁磁（FM）相互作用外，分子还允许通过不同的双线性相互作用参数 $J$ 与其最近邻（NN）发生铁磁相互作用。自旋-1 位点还受到晶体场 $D$ 的影响。通过研究零外磁场 $(H)$ 情况下磁化强度的热变化，获得了给定 $q$ 在 ($D, T$) 平面上的相图。发现相图在定性和定量上都依赖于 $q$。晶体场也被包含在内，它仅作用于自旋-1 位点。观察到三个独立的 FM 相，其 ($\sigma,S$) 在基态能级上分别为 $(1/2,1), (1/2,0)$，以及一个在较高温度范围内具有小磁化（SM）值的相区。除了从一个相到另一个相的转变区域中的重入行为外，该模型还产生了一级和二级相变。此外，还研究了 $H$ 对磁化曲线的影响，得出了相当有趣的发现。
英文摘要
Diatomic molecules consisting of one spin-1/2 ($σ$) and one spin-1 ($S$) atoms are put at each site of the Bethe lattice (BL) of the coordination number $q=3, 4$, or 6. Alongside the ferromagnetic (FM) interactions of individual atoms within a molecule, the molecules are permitted to engage in ferromagnetic interactions with their nearest neighbors (NN) through diverse bilinear interaction parameters $J$. The spin-1 sites are also under the influence of crystal field $D$. The phase diagrams on the ($D, T$) planes for a given $q$ are obtained by investigating the thermal variations of magnetizations for the case with zero external magnetic field $(H)$. It is discovered that the phase diagrams rely on $q$ both qualitatively and quantitatively. The crystal field is also included which operates only on the spin-1 sites. Three separate FM phases are observed with ($σ,S$) being $(1/2,1), (1/2,0)$ at the ground state level and a phase region with small magnetization (SM) values at a higher temperature range. In addition to the reentrant behavior in the transition zone from one phase to the other, the model produces first- and second-order phase transitions. Additionally, the impact of $H$ on the magnetization curves is examined, yielding quite intriguing findings.
Comments11 pages, 6 figures
Journal refCondens. Matter Phys. 2026, 29 (3), 33701
