中国物理B ›› 2012, Vol. 21 ›› Issue (7): 77502-077502.doi: 10.1088/1674-1056/21/7/077502

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Exchange coupling and helical spin order in the triangular lattice antiferromagnet CuCrO2 using first principles

江学范a, 刘先锋b, 吴银忠a, 韩玖荣b   

  1. a Jiangsu Key Laboratory of Advanced Functional Materials, Changshu Institute of Technology, Changshu 215500, China;
    b College of Physics Science and Technology, Yangzhou University, Yangzhou 225002, China
  • 收稿日期:2011-11-05 修回日期:2011-12-03 出版日期:2012-06-01 发布日期:2012-06-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 10874021).

Exchange coupling and helical spin order in the triangular lattice antiferromagnet CuCrO2 using first principles

Jiang Xue-Fan(江学范)a)†, Liu Xian-Feng(刘先锋)b), Wu Yin-Zhong(吴银忠)a), and Han Jiu-Rong(韩玖荣)b)   

  1. a Jiangsu Key Laboratory of Advanced Functional Materials, Changshu Institute of Technology, Changshu 215500, China;
    b College of Physics Science and Technology, Yangzhou University, Yangzhou 225002, China
  • Received:2011-11-05 Revised:2011-12-03 Online:2012-06-01 Published:2012-06-01
  • Contact: Jiang Xue-Fan E-mail:xfjiang@cslg.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 10874021).

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摘要： The magnetic and the electronic properties of the geometrically frustrated triangular antiferromagnet CuCrO2 are investigated by first-principles through density functional theory calculations within generalized gradient approximations (GGA)+U scheme. The spin exchange interactions up to the third nearest neighbours in the ab plane as well as the coupling between adjacent layers are calculated to examine the magnetism and the spin frustration. It is found that CuCrO2 has a natural two-dimensional characteristic of the magnetic interaction. Using Monte--Carlo simulation, we obtain the N閑l temperature to be 29.9 K, which accords well with the experimental value 24 K. Based on the non-collinear magnetic structure calculations, we verify that the incommensurate spiral-spin structure with (110) spiral plane is believable for the magnetic ground state, which is consistent with the experimental observations. Due to the intra-layer geometric spin frustration, parallel helical-spin chains arise along the a, b, or a+b directions each with a screw-rotation angle of about 120?. Our calculations of the density of states show that the spin frustration plays an important role in the change of d--p hybridization, while the spin-orbit coupling has very limited influence on the electronic structure.

关键词: magnetically ordered materials, multiferroic, spin frustration, spin orbit effects

Abstract: The magnetic and the electronic properties of the geometrically frustrated triangular antiferromagnet CuCrO2 are investigated by first-principles through density functional theory calculations within generalized gradient approximations (GGA)+U scheme. The spin exchange interactions up to the third nearest neighbours in the ab plane as well as the coupling between adjacent layers are calculated to examine the magnetism and the spin frustration. It is found that CuCrO2 has a natural two-dimensional characteristic of the magnetic interaction. Using Monte--Carlo simulation, we obtain the N閑l temperature to be 29.9 K, which accords well with the experimental value 24 K. Based on the non-collinear magnetic structure calculations, we verify that the incommensurate spiral-spin structure with (110) spiral plane is believable for the magnetic ground state, which is consistent with the experimental observations. Due to the intra-layer geometric spin frustration, parallel helical-spin chains arise along the a, b, or a+b directions each with a screw-rotation angle of about 120?. Our calculations of the density of states show that the spin frustration plays an important role in the change of d--p hybridization, while the spin-orbit coupling has very limited influence on the electronic structure.

Key words: magnetically ordered materials, multiferroic, spin frustration, spin orbit effects

中图分类号:  (Spin arrangements in magnetically ordered materials (including neutron And spin-polarized electron studies, synchrotron-source x-ray scattering, etc.))

  • 75.25.-j
75.50.Ee (Antiferromagnetics) 71.15.-m (Methods of electronic structure calculations) 71.70.Ej (Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect)