Related papers: Defect-impurity complex induced long-range ferroma…
In this paper, we propose a combined modeling of molecular mechanics (MM) and the tight-binding (TB) approach, which enables us to study the effect of factors such as external local forces, constraints, and vacancy defects on electronic…
We report a first-principles study of the magnetic properties, site disorder and magneto-structural coupling in multiferroic gallium ferrite (GFO) using local spin density approximation (LSDA+U) of density functional theory. The…
We study the electronic structure of the recently discovered diluted magnetic semiconductor Ga$_{1-x}$Cr$_{x}$N ($x$ = 0.01-0.10). A systematic study of the changes in the $occupied$ and $unoccupied$ ligand (N) partial density of states…
The compound alpha-Fe1.4Ga0.6O3 has been prepared by mechanical alloying of alpha-Fe2O3 and Ga2O3 and subsequent heating of the mechanical alloyed samples in vacuum condition. Magnetic ordering of alpha-Fe2O3 has been modified by…
We perform an electronic structure study for cerium oxide homogeneously-doped with cobalt impurities, focusing on the role played by oxygen vacancies and structural relaxation. By means of full-potential ab-initio methods, we explore the…
We examine the intrinsic mechanism of ferromagnetism in dilute magnetic semiconductors by analyzing the trends in the electronic structure as the host is changed from GaN to GaP, GaAs and GaSb, keeping the transition metal impurity fixed.…
We report a new biphasic crystalline wurtzite/zinc-blende homostructure in gallium nitride nanowires. Cathodoluminescence was used to quantitatively measure the wurtzite and zinc-blende band gaps. High resolution transmission electron…
We utilize a single atom substitution technique with spectroscopic imaging in a scanning tunneling microscope (STM) to visualize the anisotropic spatial structure of magnetic and non-magnetic transition metal acceptor states in the GaAs…
Wurtzite GaN is a promising material for applications in photoconductive THz radiation sources. For this purpose, the photogenerated charge carriers lifetime of the order of tenths of picoseconds is required. A controllable lifetime…
In this paper, the structural, electronic and magnetic properties of Zinc-blende Ga1-xVxSb compounds, with x from dilute doping situation to extreme doping limiting, were systematically investigated by first-principles calculations. V atoms…
The outstanding properties of high-purity germanium (HPGe) detectors, such as excellent energy resolution, high energy sensitivity, and a low background-to-signal ratio, make them essential and ideal candidates for detecting particle…
Using hybrid density functional theory, we address point defects susceptible to cause charge compensation upon Mg doping of GaN. We determine the free energy of formation of the nitrogen vacancy and of several Mg-related defects. The…
Rare-earth (RE) doped GaN is of interest for optoelectronics and spintronics and potentially for quantum applications. A fundamental understanding of the interaction between RE dopants and the semiconductor host is key to realizing the…
The electronic properties and nanostructure of InAs nanowires are correlated by creating multiple field effect transistors (FETs) on nanowires grown to have low and high defect density segments. 4.2 K carrier mobilities are ~4X larger in…
We have performed first-principle calculations of the electronic structure and exchange couplings for the nanotube compound Na$_{2}$V$_{3}$O$_{7}$ using the LDA+U approach. Our results show that while the intra-ring exchange interactions…
The study particularly focuses on the effect of the Cr co-doping on the structural, optical and magnetic properties of Zn0.99Fe0.01O. Zn0.99-xFe0.01CrxO (x =0, 0.01, 0.03 and 0.05) nanoparticles. Powder x-ray diffraction (XRD) analysis…
Formation and excitation energies as well charge transition levels, are determined forthe substitutional nitrogen (Ns),the vacancy (V) and related point defects (NV, NVH, N2, N2V and V2) by screened non-local hybrid density functional…
A microscopic model of indirect exchange interaction between transition metal impurities in dilute magnetic semiconductors (DMS) is proposed. The hybridization of the impurity d-electrons with the heavy hole band states is largely…
The electronic structure of the neutral and singly charged Mg vacancy in MgO is investigated using density functional theory. For both defects, semilocal exchange correlation functionals such as the local spin density approximation…
We demonstrate that in ferromagnetic Ga1-xMnxP exchange is mediated by holes localized in a Mn-derived band. For x<0.06, infrared absorption and photoconductivity spectra indicate the presence of a Mn impurity band which is not merged with…