Origin and Enhancement of Hole-Induced Ferromagnetism in First-Rowd0Semiconductors

Abstract

The origin of ferromagnetism in d;{0} semiconductors is studied using first-principles methods with ZnO as a prototype material. We show that the presence of spontaneous magnetization in nitrides and oxides with sufficient holes is an intrinsic property of these first-row d;{0} semiconductors and can be attributed to the localized nature of the 2p states of O and N. We find that acceptor doping, especially doping at the anion site, can enhance the ferromagnetism with much smaller threshold hole concentrations. The quantum confinement effect also reduces the critical hole concentration to induce ferromagnetism in ZnO nanowires. The characteristic nonmonotonic spin couplings in these systems are explained in terms of the band coupling model.

d° Ferromagnetism of Magnesium Oxide

“…To date, this magnetism is observed in a variety of materials with different sources of origin and is classified accordingly [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25].…”

“…Moreover, oxygen vacancies associated with misfit stress at the film substrate interface in SnO 2 , CeO 2 , Al 2 O 3 , ZnO, MgO, and HfO 2 thin films are responsible for RTFM [16]. Vacancy mediated magnetism occurs in CuO [17] and ZnO [18,19]; oxygen vacancy induced magnetism in zinc peroxide [20] and CeO 2 [21]; and surface vacancy induced magnetism in NiO [22]. Thus, these studies reveal that defects in the form of vacancies are the source of this behavior [11][12][13][14][15][16][17][18][19][20][21][22], however, sustainability of this magnetism up to long-range order requires exigency of the mechanism of interaction among these sources.…”

Density-Functional Study on the Origin of Ferromagnetism in Copper Doped Aluminium Nitride

“…By doping impurities with weaker electronegativity or lower valence into semiconductors of oxide or nitride, holes are introduced into the valence band of semiconductors, which leads to band magnetization. [13] As a nonmagnetic element, copper is often doped to many semiconductors to fabricate DMSs. Experimentally, RT ferromagnetism was reported in Cu doped ZnO, SnO 2 , and TiO 2 .…”

Is N-doped SrO magnetic? A first-principles view

“…It has no magnetic transition-metal or rare-earth element present and is free of the issue of clustering of magnetic elements, which, however, has been quite often addressed for transition-metal doped semiconductors. Thus, an observed d 0 ferromagnetism could be intrinsic, and it is important both technologically and in the viewpoint of fundamental physics.Very recently, a group of density functional calculations [11][12][13][14][15][16][17][18][19][20] suggest that when N * …”

“…Very recently, a group of density functional calculations [11][12][13][14][15][16][17][18][19][20] suggest that when N *…”