TY  - JOUR
AU  - Mavropoulos, Ph.
AU  - Lezaic, M.
AU  - Blügel, S.
TI  - Ferromagnetism in nitrogen-doped MgO: Density-functional calculations
JO  - Physical review / B
VL  - 80
IS  - 18
SN  - 1098-0121
CY  - College Park, Md.
PB  - APS
M1  - PreJuSER-6326
SP  - 184403
PY  - 2009
N1  - Record converted from VDB: 12.11.2012
AB  - The magnetic state of nitrogen-doped MgO, with N substituting O at concentrations between 1% and the concentrated limit, is calculated with density-functional methods. The N atoms are found to be spin polarized with a moment of 1 mu(B) per nitrogen atom and to interact ferromagnetically via the double-exchange mechanism in the full concentration range. The long-range magnetic order is established above a finite concentration of about 1.5% when the percolation threshold is reached. The disorder is described within the coherent-potential approximation, with the exchange interactions harvested by the method of infinitesimal rotations. The Curie temperature T-C, calculated within the random-phase approximation, increases linearly with the concentration, and is found to be about 30 K for 10% concentration. Besides the substitution of single nitrogen atoms, also interstitial nitrogen atoms, dimers and trimers, and their structural relaxations are discussed with respect to the magnetic state. Possible scenarios of engineering a higher Curie temperature are analyzed, with the conclusion that an increase in T-C is difficult to achieve, requiring a particular attention to the choice of chemistry.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000272310900061
DO  - DOI:10.1103/PhysRevB.80.184403
UR  - https://juser.fz-juelich.de/record/6326
ER  -