Related papers: Valency Configuration of Transition Metal Impuriti…
The self-interaction corrected local spin-density approximation is used to investigate the ground-state valency configuration of transition metal (TM=Mn, Co) impurities in p-type ZnO. Based on the total energy considerations, we find a…
Results from hybrid density functional theory calculations on the thermodynamic stability and optical properties of the Zn vacancy ($V_{\text{Zn}}$) complexed with common donor impurities in ZnO are reported. Complexing $V_{\text{Zn}}$ with…
We present a comprehensive study of the energetics and magnetic properties of ZnO clusters doped with 3d transition metals (TM) using ab initio density functional calculations in the framework of generalized gradient approximation + Hubbard…
Hybrid functional calculations reveal the Zn-O divacancy in ZnO, consisting of adjacent Zn and O vacancies, as an electrically active defect exhibiting charge states ranging from $2+$ to $2-$ within the band gap. Notably, the divacancy…
Self-interaction corrected local spin density approximation calculations were performed for La$_{(1-x)}$Sr$_x$MnO$_3$ (LSMO) ($0.0<x<0.5$). The influence and inter-relationship of Sr doping, magnetic structure, O displacements and phase…
Dopants of transition metal ions in II-VI semiconductors exhibit native 2+ valency. Despite this, 3+ or mixed 3+/2+ valency of iron ions in ZnO was reported previously. Several contradictory mechanisms have been put forward for explanation…
In transition metal doped ZnO, the energy position of dopant 3$d$ states relative to host conduction and valence bands is crucial in determining the possibilty of long range ferromagnetism. Density functional theory based estimates of the…
In this paper I discuss the electronic structure and properties of a specific, rather unconventional class of transition metal (TM) compounds, e.g. TM oxides, which formally have unusually high values of the oxidation state, or valence, of…
Hybrid functionals and empirical correction schemes are compared to conventional semi-local density functional theory (DFT) calculations in order to assess the predictive power of these methods concerning the formation energy and the charge…
We study theoretically the current debatable issue about the effect of transition-metal (TM) substitution in iron-based superconductors through treating all of the TM ions as randomly distributed impurities. The extra electrons from TM…
The $s,p-d$ exchange coupling between the spins of band carriers and of transition metal (TM) dopants ranging from Ti to Cu in ZnO is studied within the density functional theory. The $+U$ corrections are included to reproduce the…
We present a systematic ab initio study based on density-functional calculations to understand impurity effects in iron-based superconductors. Effective tight-binding Hamiltonians for the d-bands of LaFeAsO with various transition-metal…
We calculate the nature of magnetic interactions in transition-metal doped ZnO using the local spin density approximation and LSDA+\textit{U} method of density functional theory. We investigate the following four cases: (i) single…
Using the hybrid exchange-correlation functional within the density-functional theory, we have systematically investigated the structural and electronic properties of MO (M = Be, Mg, Ca, Sr, Ba, Zn, Cd) in binary rocksalt (B1), zincblende…
Electronic structure of the transition metal (TM) dopants in ZnO is calculated by first principles approach. Analysis of the results is focused on the properties determined by the intrashell Coulomb coupling. The role of both direct and…
We discuss the character of states near the Fermi level in Mn doped GaAs, as revealed by a survey of dc transport and optical studies over a wide range of Mn concentrations. A thermally activated valence band contribution to dc transport, a…
We study Mn substitution for Ti in BaTiO3 with and without compensating oxygen vacancies using density functional theory (DFT) in combination with dynamical mean field theory (DMFT). We find strong charge and spin fluctuations. Without…
We present first-principles based density functional theory calculations of the electronic and magnetic structure of CrO2 with 3d (Ti through Cu) and 4d (Zr through Ag) substitutional impurities. We find that the half-metallicity of CrO2…
We present the results of a computational study of ZnO in the presence of Co and Mn substitutional impurities. The goal of our work is to identify potential ferromagnetic ground states within the (Zn,Co)O or (Zn,Mn)O material systems that…
A close link between the charge transfer electronic structures and polarity dependent high-TC ferromagnetism of TM2+:ZnO DMSs (TM2+ = 3d ions) is demonstrated. Trends in ferromagnetism across the 3d series of TM2+:ZnO DMSs predicted from…