Related papers: Charge storage in oxygen deficient phases of TiO$_…
Defects in the rutile TiO${}_2$ structures have been extensively studied, but the intrinsic defects of the oxygen deficient Ti${}_n$O${}_{2n-1}$ phases have not been given the same amount of consideration. Those structures, known as…
Oxygen-deficient TiO$_2$ in the rutile structure as well as the Ti$_3$O$_5$ Magn{\'e}li phase is investigated within the charge self-consistent combination of density functional theory (DFT) with dynamical mean-field theory (DMFT). It is…
Electrochemical supercapacitors utilizing {\alpha}-MnO2 offer the possibility of both high power density and high energy density. Unfortunately, the mechanism of electrochemical charge storage in {\alpha}-MnO2 and the effect of operating…
We perform first-principles calculations of the quasiparticle defect states, charge transition levels, and formation energies of oxygen vacancies in rutile titanium dioxide. The calculations are done within the recently developed combined…
We investigate the behavior of oxygen vacancies in three different metal-oxide semiconductors (rutile and anatase TiO2, monoclinic WO3, and tetragonal ZrO2) using a recently proposed hybrid density-functional method in which the fraction of…
Structural, electronic and magnetic properties of Ti$_5$O$_9$ have been studied by \textit{ab initio} methods in low-, intermediate- and high-temperature phases. We have found the charge and orbital order in all three phases to be…
We report a comprehensive first-principles study of the thermodynamics and transport of intrinsic point defects in layered oxide cathode materials LiMO$_2$ (M=Co, Ni), using density-functional theory and the Heyd-Scuseria-Ernzerhof screened…
Cubic hafnia (HfO$_2$) is of great interest for a number of applications in electronics because of its high dielectric constant. However, common defects in such applications degrade the properties of hafina. We have investigated the…
We studied the oxygen vacancies($V_{O}$) in rutile TiO2 by using $G_0W_0$ approximation on top of GGA+$U$ as a method of choice to improve the gap. Since there is no extensive agreement regarding the characteristic of electron localization…
The Magn\'eli phase Ti$_4$O$_7$ is an important transition metal oxide with a wide range of applications because of its interplay between charge, spin, and lattice degrees of freedom. At low temperatures, it has non-trivial magnetic states…
The Magneli phase Ti4O7 exhibits two sharp jumps in resistivity with coupled structural transitions as a function of temperature at Tc1=142 K and Tc2=154 K. We have studied electronic structure changes across the two transitions using 7 eV…
Layered LiMnO$_2$ and Li$_2$MnO$_3$ are of great interest for lithium-ion battery cathodes because of their high theoretical capacities. The practical application of these materials is, however, limited due to poor electrochemical…
To gain insight into the mechanism of charge-ordering transitions, which conventionally are pictured as a disproportionation of an ion M as 2M$^{n+}$ $\rightarrow$ M$^{(n+1)+}$ + M$^{(n-1)+}$, we (1) review and reconsider the charge state…
We perform full-potential screened-hybrid density-functional theory (DFT) calculations to compare the thermodynamic stability of neutral and charged states of the surface oxygen vacancy at the rutile TiO$_2$(110) surface. Solid-state…
There have existed for a long time a paradigm that TiO phases at ambient conditions are stable only if structural vacancies are available. Using an evolutionary algorithm, we perform an ab initio search of possible zero-temperature…
Correlated band theory is employed to investigate the magnetic and electronic properties of different arrangements of oxygen di- and tri-vacancy clusters in SrTiO$_3$. Hole and electron doping of oxygen deficient SrTiO$_3$ yields various…
Understanding electronic properties of sub-stoichiometric phases of titanium oxide such as Magn\'eli phase Ti4O7 is crucial in designing and modeling resistive switching devices. Here we present our study on Magn\'eli phase Ti4O7 together…
The fate of electric dipoles inside a Fermi sea is an old issue, yet poorly-explored. Sr$_{1-x}$Ca$_x$TiO$_{3}$ hosts a robust but dilute ferroelectricity in a narrow ($0.002<x<0.02$) window of substitution. This insulator becomes metallic…
We provide a first-principles description of the crystalline and oxygen-deficient Ta2O5 using refined computational methods and models. By performing calculations on a number of candidate structures, we determined the low-temperature phase…
The formation energies of the oxygen vacancy and titanium interstitial in rutile TiO2 were calculated by the screened exchange (sX) hybrid density functional method, which gives a band gap of 3.1 eV, close to the experimental value. The O…