Possible route to d0 magnetism in α-PbO compound

Using first principles methods, we investigated the possibility of inducing d(0) magnetism in alpha-PbO. The Pb-i interstitial defect was found to acquire magnetic properties after its incorporation into the alpha-PbO crystal structure. The Pb-i interstitial defect generates a p localized state with two electrons on-site, the spin alignment of which is governed by Hund's rule, thereby leading to the formation of the local magnetic moment 2 mu(B). The magnetic coupling between defects is a function of the occupancy of the defect states. For two defects in their zero charge state Pb-i((0)), the antiferromagnetic coupling is more stable. The Pb interstitial defects in the charge state Pb-i((1+)) already have the ferromagnetic ground state. The magnetic coupling was found to be driven by long-range order interactions. The critical limit on the defect concentration required to establish magnetic percolation above room temperature is about 10(20) cm(-3), which may be possible when Pb-i defects are formed on the surface of a single crystal. The substitution of the Pb interstitial defect with the non-magnetic elements of the S(2)p(x) outer shell (the local magnetic moment is defined by 1 <= x <= 3) was found to be a potential means for tuning the magnetic behavior. (C) 2014 Elsevier Ltd. All rights reserved.