Material Design for Transparent Ferromagnets with ZnO-Based Magnetic Semiconductors

Abstract

Ferromagnetism of ZnO-based magnetic semiconductors was investigated by ab initio calculations based on the local density approximation. In a system of Mn atom doped ZnO, the ferromagnetic ordering of Mn magnetic moments was induced by hole doping. It was also found that 3d transition metal atoms of V, Cr, Fe, Co and Ni showed the ferromagnetic ordering of their magnetic moments in ZnO without any additional carrier doping treatments. Appearance of the ferromagnetism in these systems suggests possibility for a fabrication of a transparent ferromagnet which will have great impact on industrial applications in magneto optical devices.

Search for Origin of Room Temperature Ferromagnetism Properties in Ni-Doped ZnO Nanostructure

“…It also demonstrates that by simple change in the shape and size of nanomaterial it is possible to tune the physical properties of nanostructure [12][13][14] . However, present and existing theories and results [5][6][7] cannot satisfactorily articulate the origin of the witnessed ferromagnetism. Recently, RT-FM was detected in undoped in addition to nonmagnetic element doped in semiconductors.…”

“…The idea of DMS with dilute doping of magnetic elements in a host semiconductor to create the RT magnetic semiconductor was first predicted by Dielt et al 5 on the p-type wide band gap semiconductor GaN and Mn doped ZnO. Similarly Sato et al 6,7 by theoretically calculation, based on local density approximation shows ferromagnetic ordering with T C above room temperature for n- elements such as Cu, Ni, Co, Fe, Mn, etc. in a wide-gap semiconductors provides a conceivable means of tuning of both optical properties as well as ferromagnetism properties of a single material [8][9][10][11] .…”

Structure and magnetic properties of Mn-doped ZnO thin films

“…The prediction of high-temperature ferromagnetism (FM) in ZnO-based diluted magnetic semiconductors has stimulated considerable research [1][2][3]. The Mn-Zn-O system has attracted much attention because of the controversial magnetic properties reported, but their basic origins remain unclear.…”

“…The mechanism for intrinsic ferromagnetism in Zn 1−x Mn x O still remains unclear. Carrier-mediated ferromagnetism was initially proposed, and it is believed that p-type conductivity favor s this mechanism [1,2]. An alternative mechanism is the "F-center" model, in which the oxygen vacancy plays an important role [14,15].…”

Structural study of Mn-doped ZnO films by TEM

“…For example, the highest Curie temperature T c in Mn-doped GaAs is about 172K [1]. It has been theoretically predicted that, when suitably doped with transition metal ions (V, Mn, Fe, Co or Ni), ZnO might be made ferromagnetic with a Curie temperature higher than room temperature [2,3]. Extensive experiments have been carried out in many research groups in response to this prediction [4][5][6][7][8][9].…”