Crystal structure refinement of magnesium zinc divanadate, MgZnVO, from powder X-ray diffraction data.

The crystal structure of magnesium zinc divanadate, MgZnVO, was determined and refined from laboratory X-ray powder diffraction data. The title compound was synthesized by a solid-state reaction at 1023 K in air. The crystal structure is isotypic with MnZnVO (/; = 6) and is related to the crystal structure of thortveitite.

Influence of Alkaline-Earth-Metal Substitutions on the Bismuth Ruthenate Structure: BiA'RuOO' (A' = Mg, Ca, Sr).

Solid solutions with the formula of BiA'RuO (A' = Mg, Ca, Sr; 0 ≤ ≤ 0.2 for Mg, 0 ≤ ≤ 1 for Ca, and 0 ≤ ≤ 0.5 for Sr) have been synthesized and characterized.

Os Instability in the Pyrochlore Structure: TlBiOsO.

Osmium-containing oxides are rare due to the difficulty in stabilizing complex structures with a fixed stoichiometry and metastability of the phases. Bismuth-substituted thallium osmate pyrochlore samples, TlBiOsO, were synthesized using solid-state reactions where the solubility limit was found to be approximately = 1.4.

Hibonite Blue: A New Class of Intense Inorganic Blue Colorants.

Commercially available spinel cobalt blue (CoAlO) utilizes a significant amount of carcinogenic Co, which makes its synthesis more hazardous and environmentally harmful. Considerable effort has been put into developing more environmentally benign and robust blue pigments to replace cobalt blue. A new class of blue pigments with tunable hue were prepared.

Local Moment Instability of Os in Honeycomb LiOsO.

Compounds with honeycomb structures occupied by strong spin orbit coupled (SOC) moments are considered to be candidate Kitaev quantum spin liquids. Here we present the first example of Os on a honeycomb structure, LiOsO (C2/c, a = 5.09 Å, b = 8.

Structural convergence properties of amorphous InGaZnO from simulated liquid-quench methods.

The study of structural properties of amorphous structures is complicated by the lack of long-range order and necessitates the use of both cutting-edge computer modeling and experimental techniques. With regards to the computer modeling, many questions on convergence arise when trying to assess the accuracy of a simulated system. What cell size maximizes the accuracy while remaining computationally efficient? More importantly, does averaging multiple smaller cells adequately describe features found in bulk amorphous materials? How small is too small? The aims of this work are: (1) to report a newly developed set of pair potentials for InGaZnO and (2) to explore the effects of structural parameters such as simulation cell size and numbers on the structural convergence of amorphous InGaZnO.

BiCaIrO Pyrochlore Phases: Structure and Properties with Varied Ir Oxidation State from 3.9+ to 4.3.

Pyrochlore phases BiCaIrOO with x from 0.0 to 1.0 have been evaluated based on Rietveld analysis of neutron diffraction data, electrical resistivity and thermopower data from 3 to 756 K, and magnetic susceptibility data from 3 to 298 K.

From Serendipity to Rational Design: Tuning the Blue Trigonal Bipyramidal Mn Chromophore to Violet and Purple through Application of Chemical Pressure.

We recently reported that an allowed d-d transition of trigonal bipyramidal (TBP) Mn is responsible for the bright blue color in the YInMnO solid solution. The crystal field splitting between a'(d) and e'(d, d) energy levels is very sensitive to the apical Mn-O distance. We therefore applied chemical pressure to compress the apical Mn-O distance in YInMnO, move the allowed d-d transition to higher energy, and thereby tune the color from blue to violet/purple.

Influence of Structural Disorder on Hollandites A(x)Ru4O8 (A(+) = K, Rb, Rb(1-x)Na(x)).

Structural disorder can play an important role in the electrical properties of correlated materials. In this work we examine the average and local disorder in hollandites A(x)Ru4O8 (A(+) = K, Rb, Rb(1-x)Na(x)) through neutron total scattering techniques. Samples with A(+) = Rb, Rb(1-x)Na(x) exhibit the largest amount of local disorder as evidenced by higher atomic displacement parameters, and as a result, a weakened temperature dependence of the resistivity is observed upon cooling as compared to K(x)Ru4O8.

Structure and Properties of Ir-Containing Oxides with Large Spin-Orbit Coupling: Ba2In(2-x)Ir(x)O(5+δ).

In this work, the solid solution series Ba2In(2-x)Ir(x)O5+δ (x = 0-1.4, 2) was synthesized, and its structural, magnetic, and charge-transport properties were measured. With increasing Ir content, three transitions in the room-temperature structure were observed: orthorhombic to tetragonal to cubic to a monoclinic distortion of a hexagonal BaTiO3 structure.

Magnetic properties and electronic structure of manganese-based blue pigments: a high-frequency and -field EPR study.

A variety of new oxide-based materials based on hexagonal phase of YInO3 have been recently described. In some of these materials, the In(III) ions are substituted by Mn(III), which finds itself in a trigonal-bipyramidal (TBP) coordination environment. While YInO3 is colorless and YMnO3 is black, mixed systems YIn1-xMnxO3 (0.

True composition and structure of hexagonal "YAlO3", actually Y3Al3O8CO3.

The discovery of a brilliant-blue color upon the introduction of Mn(3+) to the trigonal-bipyramidal (TBP) sites in YInO(3) has led to a search for other hosts for Mn(3+) in TBP coordination. An obvious choice would be YAlO(3). This compound, which has only been prepared through a citrate precursor route, has long been considered isostructural with YInO(3).

Structural investigation of the substituted pyrochlore AgSbO3 through total scattering techniques.

Polycrystalline samples of the pyrochlore series Ag(1-x)M(n)(x)SbO(3+x[(n-1)/2]) (M = Na, K, and Tl) have been structurally analyzed through total scattering techniques. The upper limits of x obtained were 0.05 for Na, 0.

Intense turquoise and green colors in brownmillerite-type oxides based on Mn5+ in Ba2In(2-x)Mn(x)O(5+x).

Brownmillerite-type oxides Ba(2)In(2-x)Mn(x)O(5+x) (x = 0.1-0.7) have been prepared and characterized.

New layered compounds with honeycomb ordering: Li3Ni2BiO6, Li3NiM'BiO6 (M' = Mg, Cu, Zn), and the delafossite Ag3Ni2BiO6.

The new layered compound Li(3)Ni(2)BiO(6) has been prepared by a solid-state reaction. It crystallizes in the monoclinic C2/m space group; its lamellar structure is characterized by a honeycomb ordering between Ni(2+) and Bi(5+) within the slabs, while Li(+) ions occupy octahedral sites in the interslab space. Stacking defects weakly alter the XRD pattern.

Undulating layers in a new rhodate network: structure of Bi(1.4)CuORh5O10.

A new rhodate, Bi(1.4)CuRh(5)O(11), with an hitherto unknown channel structure containing undulating layers of RhO(6) octahedra sharing corners and edges has been discovered and its structure refined from single crystal X-ray diffraction data. The channels contain Bi(3+), Cu(2+), and some O strongly bound to Cu.

CsTe2O(6-x): novel mixed-valence tellurium oxides with framework-deficient pyrochlore-related structure.

Structures of CsTe₂O(6-x) phases were investigated by single-crystal X-ray diffraction and neutron powder diffraction. Stoichiometric CsTe₂O₆ is a mixed-valence Cs₂Te⁴⁺Te₃⁶⁺O₁₂ compound with a rhombohedral pyrochlore-type structure where there is complete order of Te⁴⁺ and Te⁶⁺. On heating, this compound develops significant electrical conductivity.

New oxides showing an intense orange color based on Fe3+ in trigonal-bipyramidal coordination.

Hexagonal YIn(1-x)Fe(x)O(3) phases have been prepared and characterized. The coordination for the In/Fe site in this structure is trigonal-bipyramidal. The colors of the phases change from yellow to orange to dark red with increasing Fe content.

Structural studies and electrical properties of Cs/Al/Te/O phases with the pyrochlore structure.

A series of polycrystalline and single crystal cesium aluminum tellurates with the pyrochlore structure have been prepared and characterized. The variations in cell edge for the Cs/Al/Te/O phases range from 10.06 Å for the Al rich limit to 10.

New oxides showing an intense blue color based on Mn3+ in trigonal-bipyramidal coordination.

Substitution of Mn(3+) into the trigonal-bipyramidal sites of oxides with YbFe(2)O(4)-related structures produces an intense blue color because of an allowed d-d transition. This has been demonstrated utilizing a variety of hosts including ScAlMgO(4), ScGaMgO(4), LuGaMgO(4), ScGaZnO(4), LuGaZnO(4), and LuGaO(3)(ZnO)(2). The hue of the blue color can be controlled by the choice of the host.

Mn3+ in trigonal bipyramidal coordination: a new blue chromophore.

We show that trivalent manganese, Mn(3+), imparts an intense blue color to oxides when it is introduced at dilution in trigonal bipyramidal coordination. Our optical measurements and first-principles density functional theory calculations indicate that the blue color results from an intense absorption in the red/green region. This absorption is due in turn to a symmetry-allowed optical transition between the valence-band maximum, composed of Mn 3d(x(2)-y(2),xy) states strongly hybridized with O 2p(x,y) states, and the narrow Mn 3d(z(2))-based conduction-band minimum.

Magnetodielectric effect in Bi(2)NiMnO(6)-La(2)NiMnO(6) superlattices.

Multilayer superlattices consisting of multiferroic Bi(2)NiMnO(6) (BNMO) and La(2)NiMnO(6) (LNMO) have been grown heteroepitaxially on pure and Nb-doped SrTiO(3) substrates using the pulsed laser deposition technique. In a series of superlattice structures grown with a fixed BNMO layer thickness of ten unit cells, we find that the c-axis lattice parameter, Curie temperature and magnetocapacitance are strongly dependent upon the number of stacked LNMO unit cells in the repeating units. The thickness-dependent magnetodielectric effect is attributed to the fluctuations in electric and magnetic dipole ordering due to the substrate and interface induced stress in the superlattice structures.

Tin(II) doped anatase (TiO2) nanoparticles: a potential route to "greener" yellow pigments.

During our exploration of compounds in the Sn(II)-Ti(IV)-O system, we discovered that hydrolysis of titanium alkoxide solution in the presence of Sn(II) salts resulted in stable deep-yellow colored anatase nanoparticles. The samples were characterized by X-ray powder diffraction, electron microprobe, thermal analysis, transmission electron microscopy, and (119)Sn Mössbauer spectroscopy. Mössbauer data of the yellow colored samples showed the presence of both Sn(II) and Sn(IV) in a distorted environment as expected in the anatase structure.

New A2/3-xRh2O4 compounds with the CaFe2O4 structure where A is a rare earth or Bi.

New compounds of the type R(2/3-x)Rh(2)O(4) with the CaFe(2)O(4) structure have been prepared, where R is a rare earth. For crystals grown in a Bi/V/O flux, the rare earth was partially replaced by Bi. No evidence of ordering of the A cation vacancies is found, but the A cations are displaced from the ideal A cation site by about 0.