First-principles analysis of ferromagnetism in hexagonal and rhombohedral BN

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• 作者：Ruilin Han ; Hui Yang ; Baishun Yang ; Xiaobo Du ; Yu Yan ; ^{yanyu@jlu.edu.cn} ; Hanmin Jin
• 关键词：BN ; Ferromagnetism ; First-principles
• 刊名：Journal of Magnetism and Magnetic Materials
• 出版年：2013
• 出版时间：September, 2013
• 年：2013
• 卷：342
• 期：Complete
• 页码：108-114
• 全文大小：3813 K

文摘

In view of experimental reports of ferromagnetic behaviors in the as-prepared defective BN, the effect of B and N vacancies on the magnetic properties and electronic structure of h-BN and r-BN are investigated using first-principles calculations within the generalized gradient approximation (GGA) and GGA+U scheme. The B and N vacancy induces a set of spin-polarized defect states above the valence band and below the conduction band, respectively, resulting in the formation of local magnetic moment. It is noticed that the U correction for 2p electrons plays important role in obtaining spin-polarized ground states of the h-BN and r-BN systems with B vacancy. Furthermore, the magnetic coupling between the moments induced by two B vacancies is long-range ferromagnetic and the coupling can be attributed to the p-p hybridization interaction involving holes, whereas the coupling between the moments induced by two N vacancies is anti-ferromagnetic. The calculated results suggest that the observed d⁰ ferromagnetism in the as-prepared defective BN should be attributed to the B vacancies.