Related papers: Ordered C vacancies in titanium carbides: a correl…
We revisited the problem of the stability of the superconducting state in RbxWO3 and identified the main causes of the contradictory data previously published. We have shown that the ordering of the Rb vacancies in the nonstoichiometric…
Thermodynamic, structural and electronic properties of isolated copper and iron atoms as well as their complexes with oxygen vacancies in tetragonal lead titanate are investigated by means of first principles calculations. Both dopants…
Iron oxides play an increasingly prominent role in heterogeneous catalysis, hydrogen production, spintronics and drug delivery. The surface or material interface can be performance limiting in these applications, so it is vital to determine…
Motivated by unexpected reports of a 26 K superconducting transition in elemental titanium at high pressure, we carry out an accurate ab-initio study of its properties to understand the rationale for this observation. The critical…
We point to a class of materials representing an exception to the Daltonian view that compounds maintain integer stoichiometry at low temperatures, because forming stoichiometry-violating defects cost energy. We show that carriers in the…
The origin of transition metal vacancies and their effects on the properties of ThCr2Si2-type compounds have been less studied and poorly understood. Here we carefully investigate the structure, physical properties, and electronic structure…
Replacing lithium ions with sodium ions as the charge carriers in rechargeable batteries can induce noticeable differences in the electrochemical storage mechanisms of electrode materials. Many material parameters, such as particle size,…
At high pressure, the typical behavior of elements dictated by the periodic table - including oxidation numbers, stoichiometries in compounds, and reactivity, to name but a few - is altered dramatically. As pressure is applied, the…
Carbides play a central role for the strength and ductility in many materials. Simulating the impact of these precipitates on the mechanical performance requires the knowledge about their atomic configuration. In particular, the C content…
Using an atom-vacancy exchange algorithm, we investigate the kinetics of the order-disorder transition in an fcc A_3B binary alloy model following a temperature quench from the disordered phase. We observe two clearly distinct ordering…
The thermodynamic and kinetic properties of mono and di-vacancy defects in cubic (para-electric) barium titanate are studied by means of density-functional theory calculations. It is determined which vacancy types prevail for given…
Topotactic transition is a structural phase change in a matrix crystal lattice mediated by the ordered loss/gain and rearrangement of atoms, leading to unusual coordination environments and metal atoms with rare valent states. As early as…
As pointed out by Linus Pauling in his classic work on the relationship between crystal packing and ionic radius ratio, a difference in atomic size can be accommodated more readily by an ordered structure than by a disordered one. Because…
In many materials, ordered phases and their order parameters are easily characterized by standard experimental methods. "Hidden order" refers to a phase transition in which an ordered state emerges without such an easily detectable order…
The problems of participation of crystal chemical factors in creating of conditions to occurrence of a superconducting state in layered superconductors are considered. On the basis of the experimental data, given in the literature, new…
Correlated transition metal oxides present exciting prospects as switches or memory and storage devices owing to the possibility to control electronic properties using various external stimuli. While their complex behaviour is known to stem…
A novel kind of crystal order in high-density nanoconfined bilayer ice is proposed from molecular dynamics and density-functional theory simulations. A first-order transition is observed between a low-temperature proton-ordered solid and a…
Hydrogen (H) content modifies the creep response of Fe-based alloys by altering thermodynamics of point-defects; here we identify the electronic-structure mechanism underlying this effect. Using spin-polarized first-principles calculations…
The emergence of magnetism in otherwise nonmagnetic compounds and its underlying mechanisms have become the subject of intense research. Here we demonstrate that the nonmagnetic oxygen vacancies are responsible for an unconventional…
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…