title: Magnetism in C- or N-doped MgO and ZnO: a density-functional study of impurity pairs.
abstract: It is shown that substitution of C or N for O recently proposed as a way to create ferromagnetism in otherwise nonmagnetic oxide insulators is curtailed by formation of impurity pairs, and the resultant C2 spin=1 dimers as well as the isoelectronic N2(2+) interact antiferromagnetically in p-type MgO. For C-doped ZnO, however, we demonstrate using the Heyd-Scuseria-Ernzerhof hybrid functional that a resonance of the spin-polarized C2 ppπ* states with the host conduction band results in a long-range ferromagnetic interaction. Magnetism of open-shell impurity molecules is proposed as a possible route to d(0)-ferromagnetism in oxide spintronic materials.
authors.affiliation: II. Physikalisches Institut, Universität zu Köln, Köln, Germany. wu@ph2.uni-koeln.de
authors.forename: Hua
authors.initials: H
authors.lastname: Wu
authors.forename: Alessandro
authors.initials: A
authors.lastname: Stroppa
authors.forename: Sung
authors.initials: S
authors.lastname: Sakong
authors.forename: Silvia
authors.initials: S
authors.lastname: Picozzi
authors.forename: Matthias
authors.initials: M
authors.lastname: Scheffler
authors.forename: Peter
authors.initials: P
authors.lastname: Kratzer