Ferromagnetism in phosphorus-doped ZnO: First-principles calculation (original) (raw)

Structural, electronic, and magnetic properties of Co-doped ZnO

Density functional theory based calculations have been carried out to study structural, electronic, and magnetic properties of Zn 1−x CoxO (x = 0, 0.25, 0.50, 0.75) in the zinc-blende phase, and the generalized gradient approximation proposed by Wu and Cohen has been used. Our calculated lattice constants decrease while the bulk moduli increase with the increase of Co 2+ concentration. The calculated spin polarized band structures show the metallic behavior of Co-doped ZnO for both the up and the down spin cases with various doping concentrations. Moreover, the electron population is found to shift from the Zn-O bond to the Co-O bond with the increase of Co 2+ concentration. The total magnetic moment, the interstitial magnetic moment, the valence and the conduction band edge spin splitting energies, and the exchange constants decrease, while the local magnetic moments of Zn, Co, O, the exchange spin splitting energies, and crystal field splitting energies increase with the increase of dopant concentration.

Electronic structure and magnetic studies of V-doped ZnO: ab initio and experimental investigations

Bulletin of Materials Science, 2018

In this study, the electronic structure of V-doped ZnO system is studied by means of density functional theory. Different concentrations of V and rising of Fermi level increase the relative occupation of majority/minority spin of 3d state and also induce strong spin-splitting. The existence of three different states of V spin moment has been confirmed and is found to be concentration dependent. We found that O p-orbitals are responsible for the origin of the magnetic moment. Ruderman-Kittel-Kasuya-Yosida mechanism and the atomic spin polarization of V are the key factors for the appearance of ferromagnetism in V-doped ZnO system. The synthesized nanoparticles exhibit hexagonal wurtzite crystal structure, where both crystallite size and lattice parameters vary with V content. Magnetic measurements at room temperature confirm the ferromagnetic behaviour of V-doped ZnO system.

Electronic structure and magnetic moments of 3d transition metal-doped ZnO

Journal of Magnetism and Magnetic Materials, 2004

Ferromagnetism in 3d transition metal-atom-doped ZnO was investigated by ab initio electronic structure calculations based on the generalized gradient approximation (GGA). We also performed GGA+U calculations to further refine our results. We found that Mn-doped ZnO has the largest magnetic moment and Sc-doped ZnO is nonmagnetic. Also, Mn-Co-or Cu-doped ZnO are ferromagnetic semiconductors. For the other 3d transition metal atoms the doped ZnO are metals. The appearance of ferromagnetism in these systems suggests the possibility for fabrication of a transparent ferromagnet which may have a great impact on industrial applications in magneto-optical devices.

Properties of phosphorus doped ZnO

Applied Physics A, 2007

We report the electrical and optical properties of P-doped epitaxial ZnO thin films grown heteroepitaxially on sapphire substrates or homoepitaxially on ZnO wafers grown by the hydrothermal method, respectively. As-grown heteroepitaxial thin films exhibit semi-insulating to strongly n-conducting behavior depending on the P-content and the oxygen partial pressure applied during deposition. New features are observed in the recombination spectra compared to nominally undoped ZnO thin films. The spectral position of these new features also depends on the growth conditions making a clear correlation between P-incorporation and particular spectral features feasible. For the homoepitaxially grown thin films lateral scanning capacitance microscopy measurements revealed areas of both n-and p-type majority carriers.

First-principle study of magnetism in B-doped ZnO with GGA and GGA+U

Advances in Applied Science Research, 2015

First-principles calculations are performed to study the electronic structures and magnetic properties of nonmagnetic B-doped ZnO. We investigate the following three cases: (i) single B atom substituted at Zn site, (ii) single B atom substituted at O site, and (iii) two B atoms substituted at O sites. Both generalized gradient approximation (GGA) and GGA+U calculations show that a substitutional B atom at Zn sites is non-magnetic. While a substitutional B atom at O site introduces magnetic moment of about 3.0 µB, respectively. The magnetic moment mainly comes from the partially occupied 2p orbitals of substitutional B, its nearest neighboring Zn and second neighboring O atoms, and the biggest atomic moment is of B. The U correction for the 3d Zn and for the 2p O and B states obviously changes the magnetic moment of the B atom. Total energy calculations show that the antiferromagnetic (AFM) state is predicted to be the ground state for all configuration systems.

Structural and Magnetic Properties of Transition-Metal-Doped Zn 1−x Fe x O

The ability to produce high-quality single-phase diluted magnetic semiconductors (DMS) is the driving factor to study DMS for spintronics applications. Fe-doped ZnO was synthesized by using a low-temperature co-precipitation technique producing Zn 1−x Fe x O nanoparticles (x = 0, 0.02, 0.04, 0.06, 0.08, and 0.1). Structural, Raman, density functional calculations, and magnetic studies have been carried out in studying the electronic structure and magnetic properties of Fe-doped ZnO. The results show that Fe atoms are substituted by Zn ions successfully. Due to the small ionic radius of Fe ions compared to that of a Zn ions, the crystal size decreases with an increasing dopant concentration. First-principle calculations indicate that the charge state of iron is Fe 2+ and Fe 3+ with a zinc vacancy or an interstitial oxygen anion, respectively. The calculations predict that the exchange interaction between transition metal ions can switch from the antiferromagnetic coupling into its quasi-degenerate ferromagnetic coupling by external perturbations. This is further supported and explains the observed ferromagnetic bahaviour at magnetic measurements. Magnetic measurements reveal that decreasing particle size increases the ferromagnetism volume fraction. Furthermore, introducing Fe into ZnO induces a strong magnetic moment without any distortion in the geometrical symmetry; it also reveals the ferromagnetic coupling.

Structural and electronic properties of Eu- and Pd-doped ZnO

Nanoscale Research Letters, 2011

Doping ZnO with rare earth and 4d transition elements is a popular technique to manipulate the optical properties of ZnO systems. These systems may also possess intrinsic ferromagnetism due to their magnetic moment borne on 4f and 4d electrons. In this work, the structural, electronic, and magnetic properties of Eu-and Pd-doped ZnO were investigated by the ab initio density functional theory methods based on generalized gradient approximation. The relative stability of incorporation sites of the doped elements in the ZnO host lattice was studied. The ground state properties, equilibrium bond lengths, and band structures of both the ZnO:Eu and ZnO:Pd systems were also investigated. The total and partial densities of electron states were also determined for both systems. It was found that in the ZnO:Eu system, ambient ferromagnetism can be induced by introducing Zn interstitial which leads to a carrier-mediated ferromagnetism while the ZnO:Pd system possesses no ferromagnetism.

Mechanism of ferromagnetism in non-magnetic ion-doped zinc oxides

Physica Scripta, 2014

Zinc oxide (ZnO) that contains non-magnetic ionic dopants, such as nitrogen (N)-doped zinc oxide (ZnO:N), has been observed to exhibit ferromagnetism. Ferromagnetism is proposed to arise from the Coulomb excitation in the localized states that is induced by the oxygen vacancy, V O . A model based on the Coulomb excitation that is associated with the electron-phonon interaction theoretically explains the ferromagnetic mechanism of ZnO:N. This study reveals that the ferromagnetism will be induced by either deep localized states with a small V O concentration or shallow localized states with a high V O concentration. Additionally, electron-phonon coupling either suppresses the ferromagnetism that is induced by the deep donor states of V O or enhances the ferromagnetism that is induced by the shallow donor states of V O .