ABSTRACT The phase diagrams and magnetizations in a tetragonal Ising nanoparticle have been investigated by using the effective-field theory with correlations and the core–shell model. For the spin-1/2 atoms in the shell, a transverse field is included to cant their spin direction. The results show that they are heavily dependent on the given physical parameters. The ferrimagnetic behaviours, as well as novel type behaviours, have been found in the thermal variation of magnetization. The reentrant phenomena are also obtained.

中文翻译：

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四方伊辛纳米粒子中的亚铁磁性和重入现象

摘要 通过使用具有相关性的有效场理论和核壳模型研究了四方伊辛纳米颗粒的相图和磁化强度。对于壳中的自旋 1/2 原子，包含一个横向场以倾斜它们的自旋方向。结果表明，它们严重依赖于给定的物理参数。在磁化的热变化中发现了亚铁磁行为以及新型行为。重入现象也得到了。