Effects of anharmonic lattice distortion on orbital and magnetic orderings in KCuF3
Liu Da-Yong(刘大勇)a)b), Chen Dong-Meng(陈东猛)a)c), and Zou Liang-Jian(邹良剑)a)†
a Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031, China; b Graduate School of the Chinese Academy of Sciences, Beijing 100049, China; c College of Physics Science and Technology, China University of Petroleum, Dongying 257061, China
Abstract Lattice, magnetic and orbital structures in KCuF3 are self-consistently determined by our cluster self-consistent field approach based on a spin-orbital-lattice Hamiltonian. Two stable structures are obtained and found to be degenerate, which confirms the presence of the coexistent phases observed experimentally. We clearly show that due to the inherent frustration, the ground state of the system only with the superexchange interaction is degenerate; while the Jahn--Teller distortion, especially the anharmonic effect, stabilizes the orbital ordered phase at about 23% in the x2--y2 orbit and at 77% in the 3z2--r2 orbit. Meanwhile the magnetic moment of Cu is considerably reduced to 0.56μB, and magnetic coupling strengths are highly anisotropic, Jz/Jxy $\approx$ 18. These results are in good agreement with the experiments, implying that the anharmonic Jahn--Teller effect plays an essential role in stabilising the orbital ordered ground state of KCuF3.
Received: 11 February 2009
Revised: 28 February 2009
Accepted manuscript online:
Fund: Project supported by the National
Natural Science Foundation of China (Grant Nos 90303013 and
10874186), the `100 Talents Project' and the Knowledge Innovation
Program of the Chinese Academy of
Sciences (CAS).
Cite this article:
Liu Da-Yong(刘大勇), Chen Dong-Meng(陈东猛), and Zou Liang-Jian(邹良剑) Effects of anharmonic lattice distortion on orbital and magnetic orderings in KCuF3 2009 Chin. Phys. B 18 4497
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.
