Nature of the ferromagnetic behavior and possible occurrence of the ferrimagnetic phase transition in genuinely organic molecule-based assemblages with an S=1 and S=1/2 antiferromagnetic alternating spin chain: A Green's function approach

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	Nature of the ferromagnetic behavior and possible occurrence of the ferrimagnetic phase transition in genuinely organic molecule-based assemblages with an S=1 and S=1/2 antiferromagnetic alternating spin chain: A Green's function approach
	H. H. Fu; K. L. Yao; Z. L. Liu
	2008
发表期刊	Journal of Physical Chemistry A
ISSN	1089-5639
卷号	112 期号:27 页码:6205-6210
摘要	The temperature dependence of magnetic susceptibility and sublattice magnetizations were calculated for a Heisenberg Hamiltonian of an S = 1 and S = 1/2 antiferromagnetic alternating spin chain by means of the many-body Green's function theory to show the possible occurrence of a ferrimagnetic phase transition for genuinely organic molecule-based magnets. The S = 1 site in the chain is composed of two S = 1/2 spins coupled by a finite ferromagnetic interaction. From the calculated results, it is found that the sublattice magnetization at low-spin S = 1/2 sites changes its sign from negative to positive with increasing temperature, giving rise to the spin alignments along the chain changing from anti ferromagnetic to ferromagnetic ones, which indicates that there is a magnetic phase transition occurring. Because of the weak intermolecular anti ferromagnetic interactions, the curves of the magnetic susceptibility multiplied by temperature (chi T) against temperature show a round peak at low temperatures, which is well consistent with recent experimental observations, and the ferrimagnetic phase transition could only be detected at an ultralow-temperature region and under very weak,external magnetic fields in practical organic materials. From the analysis of the sublattice magnetizations, it is uncovered that the appearance of the low-temperature peak in the curves of the chi T originates from the ferromagnetic spin alignments for all the spins along the chain, and the intermolecular antiferromagnetic interactions play a pivotal role in ferrimagnetic spin alignments of the magnetic systems. It is also found that the higher spatial symmetry of the intermolecular antiferromagnetic interactions have contributions to stabilize the ferrimagnetic ordering state in the molecule-based magnetic materials.
部门归属	[fu, hua-hua; yao, kai-lun; liu, zu-li] huazhong univ sci & technol, dept phys, wuhan 430074, peoples r china. [yao, kai-lun] chinese acad sci, int ctr mat phys, shenyang 110015, peoples r china. [liu, zu-li] nanjing univ, state key lab coordinat chem, nanjing 210093, peoples r china.;fu, hh (reprint author), huazhong univ sci & technol, dept phys, wuhan 430074, peoples r china;fuhust@yahoo.com.cn klyao@hust.edu.cn
关键词	Nitrophenyl Nitronyl Nitroxide Simple Classical Pictures Numerical-calculations Composite Molecules Magnetic-properties Building-blocks Ground-state Component Model System
URL	查看原文
WOS记录号	WOS:000257335000019
引用统计	被引频次：19[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/32759
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	H. H. Fu,K. L. Yao,Z. L. Liu. Nature of the ferromagnetic behavior and possible occurrence of the ferrimagnetic phase transition in genuinely organic molecule-based assemblages with an S=1 and S=1/2 antiferromagnetic alternating spin chain: A Green's function approach[J]. Journal of Physical Chemistry A,2008,112(27):6205-6210.
APA	H. H. Fu,K. L. Yao,&Z. L. Liu.(2008).Nature of the ferromagnetic behavior and possible occurrence of the ferrimagnetic phase transition in genuinely organic molecule-based assemblages with an S=1 and S=1/2 antiferromagnetic alternating spin chain: A Green's function approach.Journal of Physical Chemistry A,112(27),6205-6210.
MLA	H. H. Fu,et al."Nature of the ferromagnetic behavior and possible occurrence of the ferrimagnetic phase transition in genuinely organic molecule-based assemblages with an S=1 and S=1/2 antiferromagnetic alternating spin chain: A Green's function approach".Journal of Physical Chemistry A 112.27(2008):6205-6210.