Effect of oxygen and zinc vacancies in ferromagnetic C-doped ZnO: Density-functional calculations

• Published in: Journal of magnetism and magnetic materials Vol. 354; pp. 257 - 261
• Main Authors: Fang, D.Q., Zhang, R.Q., Zhang, Y., Zhang, S.L.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2014; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Density functional theory; Dilute magnetic semiconductor; Exact sciences and technology; Exchange and superexchange interactions; Ferromagnetism; Impurities; Magnetic properties; Magnetic properties and materials; Magnetic semiconductors; Magnetically ordered materials: other intrinsic properties; Mathematical analysis; Physics; Studies of specific magnetic materials; Vacancies; Zinc; Zinc oxide; Density functional theory; Dilute magnetic semiconductor; Vacancies; Doping; Ferromagnetic materials; Electronic density of states; Carbon additions; Semimagnetic semiconductors; Substitutional impurities; Impurity site; Zinc oxide; Generalized gradient approximation; Ferromagnetism; Exchange interactions
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2013.11.015

The electronic and magnetic properties of pristine and defective ZnO solids, with some O atoms substituted by C, are investigated based on density functional theory. We reveal using the GGA+U and hybrid functional calculations that two neighboring substitutional C impurities prefer to form nonmagnetic C2 dimer. Moreover, our calculations show that both oxygen and zinc vacancies suppress the ferromagnetism in C-doped ZnO and zinc vacancy can even result in antiferromagnetic coupling among C impurities, elucidating the recent experiments. •Both the GGA+U and hybrid functional calculations show that two neighboring substitutional C impurities prefer to form nonmagnetic C2 dimer.•Both oxygen and zinc vacancies suppress the ferromagnetism in C-doped ZnO.•Zinc vacancy can even result in antiferromagnetic coupling among C impurities.