Hydrothermal crystallization of Na2Ti6O13, Na2Ti3O7, and Na16Ti10O28 in the NaOH-TiO2-H2O system at a temperature of 500°C and a pressure of 0.1 GPa: The structural mechanism of self-assembly of titanates from suprapolyhedral clusters

An increase in the NaOH concentration in the NaOH-TiO₂ (rutile)-H₂O system at a temperature of 500°C and a pressure of 0.1 GPa leads to the crystallization R-TiO₂ + Na₂Ti₆O₁₃ → Na₂Ti₃O₇ → Na₁₆Ti₁₀O₂₈. Crystals of the Na₂Ti₆O₁₃ titanate (space group C2/m) have the three-dimensional framework structure Ti₆O₁₃. The structure of the Na₂Ti₃O₇ titanate (space group P2 ₁/m) contains the two-dimensional layers Ti₃O₇. The structure of the Na₁₆Ti₁₀O₂₈ titanate (space group P-1) is composed of the isolated ten-polyhedron cluster precursors Ti₁₀O₂₈. In all the structures, the titanium atoms have an octahedral coordination (MTiO₆). The matrix self-assembly of the Na₂Ti₆O₁₃ and Na₂Ti₃O₇ (Na₄Ti₆O₁₄) crystal structures from Na₄ M ₁₂ invariant precursors is modeled. These precursors are clusters consisting of twelve M polyhedra linked through the edges. It is demonstrated that the structurally rigid precursors Na₄ M ₁₂ control all processes of the subsequent evolution of the crystal-forming titanate clusters. The specific features of the self-assembly of the Na₂Ti₃O₇ structure that result from the additional incorporation of twice the number of sodium atoms into the composition of the high-level clusters are considered.     

The influences of possible factors on preparation and characterization of Lu2Ti2O7 nano-wires

Lu₂Ti₂O₇ nano-wires were obtained by the molten salt synthesis method. The morphology and structures were analyzed via SEM, TEM and XRD. XRD results indicated that the as-prepared products were mainly composed of Lu₂Ti₂O₇ phase besides only minor amounts of impurities. SEM and TEM results showed that the products consisted of wire-like nanostructures with 50–300 nm in diameter and several tens of micrometers in length. The selected area electron diffraction results indicated that the Lu₂Ti₂O₇ nano-wires were single crystalline. The influence of the calcinations temperature, holding time, salt species and amount on the crystallization habit and morphology of Lu₂Ti₂O₇ nano-wires was also studied in detail. Under the same processing conditions, KCl was proved to be more favorable for synthesis of Lu₂Ti₂O₇ nano-wires than NaCl. Furthermore, the calcinations temperature showed a strong influence on the formation of Lu₂Ti₂O₇ nano-wires. Both the increased salt content and prolonged annealing time also could improve the product morphology greatly.     

Microwave dielectric properties of (1‐x)La(Mg0.5Sn0.5)O3‐x(Sr0.8Ca0.2)3Ti2O7 ceramic system with a near zero temperature coefficient of resonant frequency

In this study, the microwave dielectric properties of (1‐x)La(Mg_0.5Sn_0.5)O₃‐x(Sr_0.8Ca_0.2)₃Ti₂O₇ ceramic system prepared by the conventional solid‐state method have been investigated for application in mobile communication. It was found that the diffraction peaks of (1‐x)La(Mg_0.5Sn_0.5)O₃‐x(Sr_0.8Ca_0.2)₃Ti₂O₇ ceramic system shift to higher angles as x increases from 0.2 to 0.4. It was also found that the X‐ray diffraction patterns of the 0.8La(Mg_0.5Sn_0.5)O₃‐0.2(Sr_0.8Ca_0.2)₃Ti₂O₇ ceramics exhibited no significant phase difference at different sintering temperatures. The average grain size of the (1‐x)La(Mg_0.5Sn_0.5)O₃‐x(Sr_0.8Ca_0.2)₃Ti₂O₇ ceramic system decreased from 6.4 to 4.3 μm as the value of x increased from 0.2 to 0.4 sintered at 1550 °C for 4 h. The dielectric constant increased from 26.6 to 35.9 and the quality factor (Q×f) decreased from 31,600 to 23,300 GHz for (1‐x)La(Mg_0.5Sn_0.5)O₃‐x(Sr_0.8Ca_0.2)₃Ti₂O₇ ceramic system as the x value increases from 0.2 to 0.4 sintered at 1550 °C for 4 h. The average value of temperature coefficient of resonant frequency (τ_f) increased from ‐18 to +8 ppm/ K as the x value increases from 0.2 to 0.4. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth of crystals of ferroelectrics Ln2Ti2O7 (LnLa?Nd) with layer-type structure

Single crystals of rare-earth (La-Nd, Sm, Gd) and Y dititanates have been grown either by the method of direct high frequency heating in cold container or/and floating zone optical technique. The crystals Ce₂Ti₂O₇ and Pr₂Ti₂O₇ belong to the structural type of Ca₂Nb₂O₇ and possess dielectric and optic characteristics which are very similar to that of known ferroelectrics La₂Ti₂O₇ and Nd₂Ti₂O₇.     

Refinement of the crystal structure of Na2Ti3O7

The crystals of Na₂Ti₃O₇ were obtained by crystallization from flux. The structure of the compound was refined from X-ray diffraction data collected on a four-circle diffractometer (2θ/θ scanning technique, λMoK _α radiation, graphite monochromator, θ_max = 40°). The crystals are monoclinic a = 9.133(2) Å, b = 3.806(1) Å, c = 8.566(2) Å, β = 101.57(3)°, sp. gr. P2₁/m, Z = 2, ρ_calcd = 3.435 g/cm³, R = 0.035, 1241 reflections with I ≥ 2σ(I). The geometric characteristics of the Ti-polyhedra are analyzed as to their positions in the trioctahedral ribbon. The polymorphism of the {Ti₃O₇}^2? anionic radical in the structures of Na₂Ti₃O₇ and PbTi₃O₇ is described. The topology and dimensionality of the { Ti₃O₇}^2? anionic radical are demonstrated to depend on the type of the large cations located at the lattice points of the hexagonal close packing characteristic of both structures.     

Advanced nanostructure Ti0.7In0.3O2 support enhances electron transfer to Pt: Used as high performance catalyst for oxygen reduction reaction

ABSTRACT

The slow rate of the oxygen reduction reaction (ORR) and the instability of Pt based catalysts are two of the most important issues which must be solved in order to make proton exchange membrane fuel cells (PEMFCs) a reality. Here, we present a new approach by exploring robust non-carbon Ti_0.7In_0.3O₂ used as a novel functionalised co-catalytic support for Pt. This approach is based on the novel nanostructure Ti_0.7In_0.3O₂ support with “electronic transfer mechanism” from Ti_0.7In_0.3O₂ to Pt that can modify surface electronic structure of Pt, owing to a shift in the d-band centre of the surface Pt atoms. The 20 wt% Pt/Ti_0.7In_0.3O₂ catalyst shows high activity than that of that of the commercial 20 wt% Pt/C (E-TEK). Our data suggest this enhancement is a result of both the electronic structure change of Pt upon its synergistic interaction with Ti_0.7In_0.3O₂ and the inherent structural and chemical stability and the corrosion-resistance of the Ti_0.7In_0.3O₂ in acidic and oxidative environments.     

On the existence of a pyrochlore-type phase in the system Bi2O3–TiO2

The existence of a bismuth titanate in the range between Bi₂Ti₄O₁₁ (Bi₂O₃ · 4 TiO₂) and Bi₄Ti₃O₁₂ (2 Bi₂O₃ 3TiO₂) has been investigated by X-ray diffraction of samples prepared by solid state reactions. For reaction temperatures above 1100 °C and a starting composition Bi₂O₃ · 2 TiO₂ there appeared additional lines which could be attributed to a cubic face-centred cell with a = 10.354 Å. A multiphase Rietveld analysis based on X-ray powder diffraction data confirmed the structural model of a pyrochlore for this compound. There is evidence that this phase belongs to the group of defect pyrochlores with a Bi³⁺-deficiency resulting in a composition of Bi_1.833Ti₂O_6.75.     

Formation and Structure of Ti?Zn-Oxides

In powder mixtures of ZnO and TiO₂ the compounds Zn₂TiO₄, ZnTiO₃ and Zn₂Ti₃O₈ can be formed as a result of solid state reactions. The mechanism of the double oxide formation is essentially determined by the microstructure of the powder mixture. Furthermore, the kind of the double oxide depends on the TiO₂-modification. There exist structural similarities between Zn₂TiO₄ (spinel) and TiO₂ (anatase) on the one hand and ZnTiO₃ and TiO₂ (rutile) on the other hand. The compound Zn₂Ti₃O₈ is formed only on the basis of the Zn₂TiO₄-phase. The crystal structure of Zn₂Ti₃O₈ was derived as a defect spinel. The unoccupied sites of cations are not arranged statistically, but they are ordered in the structure. This order leads to the decrease of the space group symmetry from Fd-3 m to P4₃32.     

Crystallographic studies of some cyclic benzylidene acetals: Key synthons for o-glycoamino acid building blocks and solid-phase oligosaccharide synthesis

Synthesis of methyl 2-azido-2-deoxy-4,6-O-benzylidene--D-galactopyranoside (1), one of the key components in the synthesis of O-glycoamino acids, was undertaken in order to synthesize Tn and TF⁽³⁾ antigen building blocks. In pursuit of an alternative approach, benzylidenation of the crude D-galactal (2a) afforded methyl 2-deoxy-4,6-O-benzylidene--D-galactopyranoside (3c) and 3,4-O-benzylidene-D-galactal (3b) besides the expected 4,6-O-benzylidene-D-galactal (3a). Formation of compound 3c was explained based on the presence of methyl 2 deoxy--D-galactopyranoside (2b) isomer and/or trace amount of methanol in the crude mixture of deacetylated product of 2 prior to benzylidenation. On the other hand, formation of 3b in substantial quantities appears to be a thermodynamically controlled product and its formation is found to be common during prolonged Lewis-acid catalyzed benzylidenation reaction. Crystal structures of these important and useful precursors were deduced by X-ray diffraction methods to enumerate their complete molecular structure as well as to understand the effect of the cyclic acetal on the pyranose ring conformation. Compound 1 crystallizes in the orthorhombic space group P2 ₁ 2 ₁ 2 ₁ with cell dimensions a = 5.058(7), b = 12.766(7), c = 22.557(7) Å 3b crystallizes in the hexagonal space group P6 ₁ with cell dimensions a = 18.265(4), b = 18.265(3), c = 6.323(2) Å 3c crystallizes in the monoclinic space group P2 ₁ with cell dimensions a = 10.614(3), b = 4.963(2), c = 12.730(3) Å, and = 95.47(3)°.     

Crystal structure of β′-Zn2V2O7

The crystal structure of the high-temperature modification of zinc pyrovanadate, namely, β′-Zn₂V₂O₇, is refined by the full-profile Rietveld method (GSAS) using the high-temperature X-ray diffraction data. The crystals are monoclinic (space group C2/m, Z = 2); the unit cell parameters are as follows: a = 6.9324(2) Å, b = 8.4394(2) Å, c = 5.0326(1) Å, and β = 108.272(2)°. Comparative analysis of the crystal structures of β′-Zn₂V₂O₇, β-Mn₂V₂O₇, and Cd₂V₂O₇ is performed.     

Crystal structures of four inclusion compounds of 2,2′-dithiosalicylic acid and tetraalkylammonium

Herein four inclusion compounds of 2,2′-dithiosalicylic acid and tetraalkylammonium, 2(CH₃)₄N⁺·C₁₄H₈O₄S₂^2?·H₂O (1), (C₂H₅)₄N⁺·C₁₄H₉O₄S₂^?·0.25H₂O(2), (n-C₃H₇)₄N⁺·C₁₄H₉O₄S₂^? (3) and (n-C₄H₉)₄N⁺·C₁₄H₉O₄S₂^?(4) are prepared and characterized by X-ray single crystal diffraction. As shown in the results, compounds 1 and 3 belong to orthorhombic crystal system with different space groups of P2₁2₁2₁ and Pca2₁, and 2 and 4 are monoclinic system with similar groups of P2₁/n and P2₁/c. The crystallography data are displayed below: 1: a = 10.5903(7) Å, b = 10.6651(7) Å, c = 21.9476(13) Å, V = 2478.9(3) ų, Z = 4, R₁ = 0.0359; 2: a = 8.13340(1) Å, b = 22.0741(3)Å, c = 13.2143(2)Å, β = 101.6360(1) °, V = 2323.70(6) ų, Z = 1, R₁ = 0.0385; 3: a = 15.7857(2) Å, b = 8.24830(1) Å, c = 20.2599(2) Å, V = 2637.94(5) ų, Z = 4, R₁ = 0.0308_degree4: a = 11.7476(2) Å, b = 17.1346(1) Å, c = 16.3583(3)Å, β = 109.4560(1) °, V = 3104.74(9)ų, Z = 4, R₁ = 0.0562. Interestingly, although the carbon chains of the guest templates vary from methyl group to butyl group, the host molecules of 2,2′-dithiosalicylic acid all construct the similar 2D hydrogen-bonded host layers with or without the existence of water molecules to contain the guest templates to yield analogous sandwich-like inclusion compounds. Obviously, although the guest templates will have certain effects on the ultimate formation of these crystal structures, the host molecule of 2,2′-dithiosalicylic acid is a controlling factor to form these four inclusion compounds.     

Crystal Structure and Vibrational Spectra of Erbium Trisodium Bis(Cyclotriphosphate) Nonahydrate,ErNa<Subscript>3</Subscript>(P<Subscript>3</Subscript>O<Subscript>9</Subscript>)<Subscript>2</Subscript> · 9H<Subscript>2</Subscript>O

Abstract The cyclotriphosphate salt, ErNa₃(P₃O₉)₂ · 9H₂O, has been characterized by single-crystal X-ray diffraction [hexagonal, space group , with unit cell parameters of a = b = 30.8451(14), c = 12.8063(8) ?; Z = 18]. The structure consists of alternating layers of [P₃O₉]³⁻ groups, ErO₈ dodecahedra, Na(1)O₆ and Na(2)O₇ polyhedra linked together by water molecules. The P₃O₉ rings are grouped along the c-axis in a P₃O₉–ErO₈ arrangement thereby producing broad, hexagonal channels of diameter of 6.65 ? with a side dimension of 3.907 ?. The absence of coincidences for the majority of the IR and Raman bands observed for the cyclotriphosphate salt is in accord with the centrosymmetric structure of the material. The vibrational spectra have been interpreted on the basis of factor group effects. Graphical abstract We report the crystal structure and vibrational spectra of erbium trisodium bis(cyclotriphosphate)nanohydrate salt ErNa ₃ (P ₃ O ₉ ) ₂ · 9H ₂ O H. Assaaoudi, M. Ijjaali, A. Ennaciri, I. S. Butler* and J. A. Kozinski Crystal structure and vibrational spectra of erbium trisodium bis(cyclotriphosphate) nonahydrate,ErNa₃(P₃O₉)₂ · 9H₂O. Projection of the coordination polyhedra of ErNa₃(P₃O₉)₂ · 9H₂O down the c axis     

Vitrification and crystallization in the system of K2O-B2O3-TiO2

The vitrification and crystallization behavior of melts produced at 1400 °C in the ternary system of K₂O-B₂O₃-TiO₂ is investigated. It is shown that there are two fields of compositions (indicated in mol%) which allow obtaining the glass-ceramic materials with continuous glassy matrix after the cooling of molten compositions. In the first field [TiO₂] = 25-57, [K₂O] = 30-50 and [B₂O₃] = 0-25, the glass-ceramics consisted of the potassium-titanium-borate glassy phase and different crystalline potassium titanates (K₄Ti₃O₈, K₂Ti₂O₅, K₂Ti₄O₉, K₂Ti₆O₁₃). The ratio of TiO₂:K₂O in the obtained titanates increases with [TiO₂] and [B₂O₃]. In the second field, [TiO₂] = 7-37, [K₂O] = 0-25 and [B₂O₃] = 52-93, the obtained glass-ceramics consisted of a similar vitreous phase, as mentioned above, and TiO₂ crystals. During the cooling of the melts, short whiskers-like crystals of anatase formed in the compositions with relatively low [TiO₂] and relatively high [K₂O], whereas long fiber-shaped crystals of rutile appeared with the compositions characterized with relatively high [TiO₂] and relatively low [K₂O]. The possible application of the obtained glass-ceramic materials as a source of fibrous TiO₂, for composite reinforcement, and as solid lubricants is discussed.     

An easy sol–gel route for deposition of oriented Ln2Ti2O7 (Ln=La,Nd) films on SrTiO3 substrates

The effect of the orientation of SrTiO₃ (STO) substrates, (1 0 0) or (1 1 0), on the growth of La₂Ti₂O₇ (LTO) and Nd₂Ti₂O₇ (NTO) thin films was investigated. The films were deposited via a sol–gel process coupled to the spin-coating technique. Depending on the substrate orientation, a similar effect was observed on the structural properties for both the LTO and NTO thin films. For (1 1 0)-oriented STO substrate, the films are preferentially (0 0 1) oriented while for (1 0 0)-oriented STO substrates, the orientation is mainly (0 1 2). Those matching appear to be in good agreement with the compatibility between the film/substrate crystal lattices, in relation with the existence of perovskite slabs in Ln₂Ti₂O₇ (Ln=rare earth) compounds. In these latter, a slight disorientation of the (0 1 2) planes with respect to the surface of the substrate was measured. This tilting is even more marked in the case of NTO. The surface morphology was studied by atomic force microscopy.     

Crystal Structures of a Series of Bis{(2-Aminobenzoyl-)amino}alkanes

Abstract  The crystal structures of 1,2-bis-{(2-aminobenzoyl-)amino}ethane(1), 1,4-bis-{(2-aminobenzoyl-)amino}butane(2) and 2,2-dimethyl-1,3-bis-{(2-aminobenzoyl-)amino}-propane(3) have been determined by single crystal X-ray diffraction analysis. 1 and 2 are centrosymmetric molecules which lie on crystallographic centers of symmetry and adopt extended conformations. On the other hand, owing to the odd number of carbon atoms in the spacer unit, 3 does not show centrosymmetry, but crystallizes in a non-centrosymmetric space group and assumes a folded conformation. The crystal structures of 1, 2 and 3 are compared with the known structures of anthranilamide (7) and the N-alkyl anthranilamide derivative 8. Crystal data: 1 C₁₆H₁₈N₄O₂, monoclinic, space group P2₁/a, a = 9.5262(8) ?, b = 5.4200(5) ?, c = 15.3821(14) ?, β = 105.980(5)° and V = 763.52(12) ?³, for Z = 2. 2 C₁₈H₂₂N₄O₂, monoclinic, space group C2/c, a = 32.0710(17) ?, b = 5.4732(4) ?, c = 9.7326(5) ?, β = 102.570(4)° and V = 1667.42(17) ?³, for Z = 4. 3 C₁₉H₂₄N₄O₂, orthorhombic, space group Pca2₁, a = 16.7676(4) ?, b = 10.1847(2) ?, c = 10.5338(5) ?, and V = 1798.89(7) ?³, for Z = 4. Index Abstract  The crystal structures of 1,2-bis-{(2-aminobenzoyl-)amino}ethane(1), 1,4-bis-{(2-aminobenzoyl-)amino}butane(2) and 2,2-dimethyl-1,3-bis-{(2-aminobenzoyl-)amino}-propane(3) have been determined by single crystal X-ray diffraction analysis. 1 and 2 are centrosymmetric molecules which lie on crystallographic centers of symmetry and adopt extended conformations, whereas 3 does not show centrosymmetry, but crystallizes in a non-centrosymmetric space group and assumes a folded conformation.      

X-ray absorption near edge structure analysis of valence state and coordination geometry of Ti ions in borosilicate glasses

The effects of borosilicate glass composition and melting condition on valence state and coordination geometry of polyvalent Ti ions have been studied by X-ray absorption experiments. The results indicate that most of Ti³⁺ ions are oxidized into Ti⁴⁺ ions when Ti₂O₃ is doped into sodium borosilicate glasses. When TiO₂ is doped into sodium borosilicate glasses, almost all of titanium ions are in the form of Ti⁴⁺. Doping both graphite and titanium oxide simultaneously in borosilicate glasses favors the formation of small amounts of Ti³⁺ ions. Ti⁴⁺ ions occupy both fivefold and sixfold coordinated sites in borosilicate glasses with non-bridging oxygen (NBS1), mainly fivefold coordinated sites. For borosilicate glasses without non-bridging oxygen (NBS2), Ti⁴⁺ ions are in both fourfold and fivefold coordinated sites. Using reducing agents during melting procedure favors the formation of fourfold coordinated Ti⁴⁺ ions in NBS2.     

Synthesis and X-Ray Crystal Structure of 1- and 2-Cinnamoyaloxy Acetonaphthones

Abstract  

The synthesis of titled compounds were achieved in one step using hydroxyl naphthones and substituted cinnamic acids in the presence of a catalytic amount of phosphorus oxychloride. X-ray crystal studies were undertaken for three compounds and the results are presented. Compounds 1 (C₂₂H₁₅F₃O₃) and 3 (C₂₁H₁₅BrO₃) formed a monoclinic crystals while compound 2 (C₂₂H₁₅F₃O₃) formed a triclinic crystals. The observed space group of these compounds is P2₁/c and P[`1] \bar{1} respectively. The 2-substituted compounds showed identical space group and showed a perpendicular arrangements of each of the substituents to the plane of the naphthyl ring. On the contrary, the 1-substituted cinnamoyal compound showed an orthogonal arrangement to naphthyl ring but the acetyl group was almost planar relative to the naphthyl moiety. The characterization of the structures of the compounds was also accomplished using high-resolution NMR spectroscopic techniques.     

Ti/Zr isomorphism in wadeite: The crystal structure of the titanium-dominant K<Subscript>2</Subscript>(Ti<Subscript>0.55</Subscript>Zr<Subscript>0.45</Subscript>)Si<Subscript>3</Subscript>O<Subscript>9</Subscript> member of the series

The crystal structure of the titanium-rich mineral wadeite K₂(Ti_0.55Zr_0.45)Si₃O₉ from rischorrites of the Khibiny Alkaline Massif (Kola Peninsula, Russia) is studied by X-ray diffraction (XCalibur-S diffractometer, R = 0.0459): a = 6.8611(6) Å and c = 10.0611(9) Å; space group P6₃/m, Z = 6, D _x = 3.03 g/cm³. It is shown that the unit-cell parameters and volume of the mineral of mixed (Ti/Zr) composition are naturally intermediate between those of the terminal members of the isomorphous wadeite-based K₂ZrSi₃O₉–K₂(Ti_0.55Zr_0.45)Si₃O₉–K₂TiSi₃O₉ series. The expected correlation is due to the ionic radii of Zr⁴⁺ and Ti⁴⁺ which determine the lengths of Zr/Ti–O bonds in octahedra. The data of field observations and microscopic studies show that the Ti-dominant wadeite is formed on the basis of primary zirconium mineral in the course of a late imposed process under unique geochemical conditions.     

Neutron diffraction investigation of the evolution of the crystal structure of oxygen-conducting solid solutions (Yb1 ? x Ca x )2Ti2O7 ( x = 0, 0.05, 0.10)

The crystal structure of pyrochlore-like solid solutions (Yb_{1 − x} Ca _x )₂Ti₂O₇ (x = 0, 0.05, 0.10) synthesized by high-temperature annealing of mechanically activated initial oxides at temperatures of 1300–1500°C is studied using neutron diffraction. It is found that the Ca²⁺ cations are located in the ytterbium sublattice, which apparently favors the splitting of one of the oxygen sublattices [O(2) (48f)] of the pyrochlore structure: the decrease in the occupancy of this sublattice is accompanied by the formation of a new sublattice O(3) (8b), whereas the other oxygen sublattice O(1) (8a) remains unchanged. This rearrangement of the anions in the oxygen subsystem due to the incorporation of an alkaline-earth cation explains the high ionic conductance (∼0.2 S/cm at 1000°C) for (Yb_0.9Ca_0.1)₂Ti₂O₇ ∼ 0.2, which is the maximum value observed to date for pyrochlores of the A ₂ B ₂O₇ type, where A = Ln and B is a Subgroup IVA element of the periodic system. The bulk and grain-boundary components of the conductivity of (Yb_0.95Ca_0.05)₂Ti₂O₇ synthesized at temperatures of 1300, 1400, and 1500°C are studied using impedance spectroscopy. It is found that the (Yb_0.95Ca_0.05)₂Ti₂O₇ sample synthesized at 1500°C has the highest total conductivity due to the increased grain-boundary component. The bulk component of the ionic conductivity of (Yb_0.95Ca_0.05)₂Ti₂O₇ is hardly affected by the synthesis temperature and depends mainly on the degree of heterovalent substitution. Original Russian Text ? A.V. Shlyakhtina, A.E. Sokolov, V.A. Ul’yanov, V.A. Trunov, M.V. Boguslavskiĭ, A.V. Levchenko, L.G. Shcherbakova, 2009, published in Kristallografiya, 2009, Vol. 54, No. 1, pp. 31–36.     

One‐step fabrication of SnxTi1‐xO2 rutile‐type core‐shell microspheres and their electrochemical properties

Sn_xTi_1‐xO₂ core‐shell microspheres were synthesized through a simple one‐step hydrothermal method. The structural and morphologic properties were unambiguously characterized, and the electrochemical performance of the Sn_xTi_1‐xO₂ microspheres was determined by cyclic voltammetry. The possible formation mechanism of Sn_xTi_1‐xO₂ microspheres was also proposed.