相关论文: Crystal structure of cobalt hydroxide carbonate Co…
Knowledge of the atomic geometry of a surface is a prerequisite for any detailed understanding of the surface's electronic structure and chemical properties. Previous studies have convincingly demonstrated that density functional theory…
Single-phased La0.6Sr0.4Co1-yFeyO3-d (y = 0.2, 0.5, 0.8) nanorods exhibiting the rhombohedral perovskite-type phase were synthesized by a pore-wetting technique. We studied their chemical composition, crystal and electronic structures,…
In this work, we investigate the representative case of the homometallic Co ludwigite Co$^{2+}_2$Co$^{3+}$O$_2$BO$_3$ ($Pbam$ space group) with four distinct Co crystallographic sites [$M1$-$M4$] surrounded by oxygen octahedra. The…
A new polymorph of volborthite [tricopper(II) divanadium(V) heptaoxide dihydroxide dihydrate], Cu3V2O7(OH)2 2H2O, has been discovered in a single crystal prepared by hydrothermal synthesis. X-ray analysis reveals that the monoclinic…
We have synthesized various samples of the $x=2/3$ phase of sodium cobaltate Na$_{x}$CoO$_{2}$ and performed X-ray powder diffractions spectra to compare the diffraction with the structure proposed previously from NMR/NQR experiments [H.…
The synthesis conditions of SrTiO$_3$(Co) samples in which cobalt predominantly enters the $A$ or $B$ sites of the perovskite $AB$O$_3$ structure are found. EXAFS studies show that the Co impurity at the $A$ site is off-center and is…
Biotite crystals are phyllosilicate trioctahedral micas with the general chemical formula K(Mg,Fe)3AlSi3O10(OH)2 that form a solid-solution series with iron-poor phlogopite and iron-rich annite endmembers. With a wide band gap energy and a…
Using density functional theory plus self-consistent Hubbard $U$ (DFT$+U_{sc}$) calculations, we have investigated the structural and electronic properties of the rare-earth cobaltites \textit{R}CoO$_3$ (\textit{R} = Pr -- Lu). Our…
Transition-metal dichalcogenides of the pyrite-marcasite family are model systems of crystal chemistry. A few of these show polymorphism. The theoretical ground state of CoSe2 is marcasite, but the material is typically synthesized in the…
La-Co-Ni oxides were fabricated in the form of thin-film materials libraries by combinatorial reactive co-sputtering and analyzed for structural and functional properties over large compositional ranges: normalized to the metals of the film…
The crystal structure of Lanthanum Cerium Oxide (La$_2$Ce$_2$O$_7$) is investigated using \textit{ab initio} density functional theory (DFT) calculations. The relative stability of fluorite- and pyrochlore-like structures is studied through…
We investigate the crystal structure and the electronic properties of the trilayer nickelate La$_4$Ni$_3$O$_{10}$ by means of quantum mechanical calculations in the framework of the density functional theory. We find that, at low…
The crystalline structure of ground-state orthorhombic SrRuO$_3$ is reproduced by applying hybrid density functional theory scheme to the functionals based on the revised generalized-gradient approximations for solid-state calculations. The…
Iron oxides and oxyhydroxides are challenging to model computationally as competing phases may differ in formation energies by only several kJ/mol, they undergo magnetization transitions with temperature, their structures may contain…
The local structure and oxidation state of the cobalt impurity in SrTiO$_3$ is studied by X-ray absorption fine structure (XAFS) spectroscopy. The synthesis conditions, under which cobalt predominantly (up to 76%) substitutes the atoms at…
The crystal structure and oxygen stoichiometry in two-layer Na0.74CoO2 and Na0.38CoO2 at room temperature are analyzed by powder neutron diffraction. Two sets of diffraction data for each sample, taken at different incident neutron…
Powder X-ray diffraction (PXRD) and neutron powder diffraction (NPD) have been used to investigate the crystal structure of CoFe2O4 nanoparticles prepared via different hydrothermal synthesis routes, with particular attention given to…
The crystal structures of the NaxCoO2 phases based on three-layer NaCoO2, with x=0.32, x=0.51, x=0.60, x=0.75 and x=0.92, determined by powder neutron diffraction, are reported. The structures have triangular CoO2 layers interleaved by…
We studied the crystal and magnetic structure of the La$_{1-x}$Ca$_{x}$MnO$_{3}$ compound for $(0.11\leq x\leq 0.175)$ using stoichiometric samples. For $x<0.13$ the system's ground state is insulating canted antiferromagnetic. For $0.13\le…
Experimental data on the structure of ferroelectric oxide Bismuth Titanate suggests two different kinds of structures i.e. orthorhombic and monoclinic. We have performed density functional theory (DFT) based first principle calculations to…