Thermodynamic properties of Heisenberg ferrimagnetic spin chains: Ferromagnetic-antiferromagnetic crossover

被引:107
作者
Yamamoto, S [1 ]
Fukui, T
机构
[1] Okayama Univ, Fac Sci, Dept Phys, Okayama 700, Japan
[2] Kyoto Univ, Inst Adv Energy, Uji, Kyoto 611, Japan
关键词
D O I
10.1103/PhysRevB.57.R14008
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
We study thermodynamic properties of the one-dimensional Heisenberg ferrimagnet with antiferromagnetically exchange-coupled spins of two kinds. The specific heat and the magnetic susceptibility are calculated employing a modified spin-wave theory as well as a quantum Monte Carlo method. The specific heat is proportional to T-1/2 at low enough temperatures but shows a Schottky-like peak at mid temperatures. The susceptibility diverges as T-2. We reveal that at low temperatures the model acts as a ferromagnet, while at mid temperatures it behaves like a gapped antiferromagnet.
引用
收藏
页码:R14008 / R14011
页数:4
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