Origin of ferromagnetism in molybdenum dioxide from ab initio calculations
2010 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 81, no 1, 012402- p.Article in journal (Refereed) Published
We have performed spin-polarized calculations of the unexpected ferromagnetism in ultrathin films of molybdenum dioxide (MoO2) within the framework of density-functional theory. It is found that the ideal bulk MoO2 is metallic and nonmagnetic. Bulk MoO2 with Mo vacancy, O vacancy, Mo interstitial, or O interstitial remains to be nonmagnetic. Using slab calculation, we observed ferromagnetism in both oxygen-rich and -poor MoO2 (100) surfaces with average surface magnetic moment 1.53 and 0.69(mu B) per surface Mo atom, respectively. The partial density of states of surface Mo atom at the Fermi level (E-F) is much larger than that of the Mo atom in the center of the slab and in bulk MoO2, which indicates that ferromagnetism in surface (100) is due to Stoner instability. Enrichment of oxygen at the surface is found to be more favorable for ferromagnetism in MoO2 (100). The 2p states of surface oxygen atoms are significantly hybridized with the 4d states of Mo atoms and are appreciably spin polarized.
Place, publisher, year, edition, pages
2010. Vol. 81, no 1, 012402- p.
IdentifiersURN: urn:nbn:se:uu:diva-137391DOI: 10.1103/PhysRevB.81.012402ISI: 000274001800010OAI: oai:DiVA.org:uu-137391DiVA: diva2:378805