Magnetization processes and existence of reentrant phase transitions in coupled spin-electron model on doubly decorated planar lattices

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:452

Article

Cencarikova, Hana¹  Strecka, Jozef²  Gendiar, Andrej³ 

[1] Slovak Acad Sci, Inst Expt Phys, Watsonova 47, SK-04001 Kosice, Slovakia

[2] Safarik Univ, Fac Sci, Dept Theoret Phys & Astrophys, Pk Angelinum 9, SK-04001 Kosice, Slovakia

[3] Slovak Acad Sci, Inst Phys, Dubravska Cesta 9, SK-84511 Bratislava, Slovakia

关键词: Strongly correlated systems;    Ising spins;    Mobile electrons;    Reentrant phase transitions;    Metamagnetic transitions;   

DOI  :  10.1016/j.jmmm.2017.10.056

来源: Elsevier

【 摘 要 】

An alternative model for a description of magnetization processes in coupled 2D spin-electron systems has been introduced and rigorously examined using the generalized decoration-iteration transformation and the corner transfer matrix renormalization group method. The model consists of localized Ising spins placed on nodal lattice sites and mobile electrons delocalized over the pairs of decorating sites. It takes into account a hopping term for mobile electrons, the Ising coupling between mobile electrons and localized spins as well as the Zeeman term acting on both types of particles. The ground-state and finite-temperature phase diagrams were established and comprehensively analyzed. It was found that the ground-state phase diagrams are very rich depending on the electron hopping and applied magnetic field. The diversity of magnetization curves can be related to intermediate magnetization plateaus, which may be continuously tuned through the density of mobile electrons. In addition, the existence of several types of reentrant phase transitions driven either by temperature or magnetic field was proven. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

Free