12137-20-1Relevant articles and documents
Boyant, R. T.
, p. 62 - 68 (1962)
Composition dependent semiconductor-metal transition in new mixed valent Ti-oxides
Kodenkandath, Thomas
, p. 1587 - 1592 (1997)
A composition dependent semiconductor-metal transition is observed in a new series of Ti oxides of the type LnBa2Ti3Oy (Ln = La, Gd and Y) in which Ti is in lower and/or mixed valent state. The new phases have been synthesised by the dc arc melting technique and characterised by powder X-ray diffraction, thermal analysis, electrical and magnetic measurements. Single phase compounds are found to form only when the nominal (average) Ti valence (VTi) is between 3.67 to 2.33. The crystal structure is simple cubic in which Ln/Ba and various Ti ions occupy respectively the A- and B-sites of a disordered ABO3 perovskite type lattice. The semiconductor-metal transition is also found to depend on the VTi. The compounds show semiconducting behaviour for 3.67 Ti > 2.67 and are metallic when VTi = 2.33 which is the lowest possible value of VTi in the system. No evidence for superconductivity has been observed in any of the metallic compositions down to 15 K.
Growth of ordered titanium oxide films on Ag(100)
Kaneko,Ono,Ozawa,Edamoto
, p. 32 - 35 (2007)
Titanium oxide films grown on Ag(100) have been investigated with low-energy electron diffraction, X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. As Ti is deposited on Ag(100) at room temperature in an O2 atmosphere at 10-5-10-7?Torr, a disordered TiO2-like film is formed. As the surface is subsequently heated at 600 {ring operator}C, though the composition of the film is nearly unchanged, the film changes into an ordered film with (5×1) periodicity [(5×1) TiO2 film]. On the other hand, as Ti is deposited in O2 at 5.0×10-9-1.0×10-8?Torr, a disordered TiO-like film is formed. As the surface is subsequently heated at 600 {ring operator}C, the composition of the film is nearly unchanged and the film changes into an ordered film with (1×1) periodicity [(1×1) TiO film]. Ultraviolet photoelectron spectroscopy measurements show that the (1×1) TiO film has an electronic state around the Fermi level, and the state is ascribed to a partially filled Ti 3d state which has been theoretically expected to exist in a TiO crystal.
TiO epitaxial film growth on MgO(001) and its surface structural analysis
Suzuki, Taku,Souda, Ryutaro
, p. 506 - 511 (2000)
The metallic TiO single crystal film formed epitaxially on MgO is reported. It was found that the simultaneous supply of Ti vapor and O2 gas on the MgO(001) surface resulted in the TiO(001) film formation. The surface structure of the TiO(001)
Reaction between titanium and zirconia powders during sintering at 1500°C
Lin, Kun-Lin,Lin, Chien-Cheng
, p. 2220 - 2225 (2007)
Zirconia-titanium (ZrO2-Ti) composites have been considered potential thermal barrier graded materials for applications in the aerospace industry. Powder mixtures of Ti and 3 mol% Y2O3 partially stabilized ZrO2 in various ratios were sintered at 1500°C fo
Investigation of the electrochemical reduction of Na2Ti3O7 in CaCl2 molten salt
Liu, Kejia,Wang, Yaowu,Di, Yuezhong,Peng, Jianping
, p. 236 - 243 (2019)
Sodium titanate (Na2Ti3O7), as an intermediate product for producing TiO2 through alkaline process, was used as precursor to prepare Ti metal successfully by FFC Cambridge Process. For the aim to gain insight into the electro-reduction mechanism, the sintered Na2Ti3O7 pellets(～1.83 mm thinkness, open porosity ～20%) were electrolysed using them as cathodes against graphite counter electrode in the molten CaCl2. The experiments were carried out at 900 °C and the applied voltage was 3.1V. Partially reduced samples were prepared by terminating the reduction process after different electrolysis times. The obtained samples were characterised by means of X-ray diffraction analysis, SEM and EDS. The results show that Na2Ti3O7 reacts easily with molten CaCl2 as 2Na2Ti3O7 + 2CaCl2 → Ca2Ti2O6 + 4TiO2 + 4NaCl and Ca2Ti2O6 → 2CaTiO3. The electrochemical reduction of sodium titanate proceeds via sequential formation of CaTiO3, titanium sub-oxides (such as Ti4O7, Ti3O5, Ti2O3 and TiO), CaTi2O4, Ti-O solid solution and Ti. The whole reduction can be divided into three stages: the first stage is that Ca2+ ions from electrolyte are inserted into Na2Ti3O7 particles leading to the formation of titanium sub-oxides and calcium titanates(CaTiO3 and CaTi2O4); the second stage is that calcium titanates are reduced into Ti-O solid solution from outside to inside of the pellets; the third stage is that the formed Ti-O solid solution is further deoxidised to form Ti metal.
Preparation and characterization of vanadium oxide deposited on thermally stable mesoporous titania
Segura,Chmielarz,Kustrowski,Cool,Dziembaj,Vansant
, p. 948 - 955 (2006)
Vanadium oxide was deposited on mesoporous titania by the molecular designed dispersion method to investigate the potential properties of these catalysts. Mesoporous titania was synthesized following the evaporation-induced self-assembly (EISA) method with a subsequent treatment with ammonia to increase the thermal stability. As a result, the mesoporous titania obtained shows a high surface area (～350 m2/g) and high stability. Vanadium oxide was deposited by the MDD method using a vanadyl acetylacetonate complex that was transformed into VOx after a controlled calcination in air flow at 300 °C. The mesostructure and porosity characteristics of titania remain even until the maximum V-loading was reached (0.4 mmol/g), as it was shown by N: sorption measurements at -196 °C. The catalysts were characterized by chemical analysis, Fourier transform infrared-photoacoustic spectroscopy (FTIR-PAS), UV-vis diffuse reflectance (DR), and Fourier transform Raman spectroscopy. Raman spectra showed isolated V species for the different V-containing catalysts. Furthermore, UV-vis-DR revealed a higher contribution of polymeric species as the V loading increases. The VOx/mesoporous titania catalysts were highly active in the selective catalytic reduction of NOx. A high activity in the NO conversion was observed, which increases with increasing metal loading.
Growth, Structure, and Electrophysical Properties of Single Crystals of A2TiGeO5 (A = Li and Na)
Kireev,Yakubovich,Ivanov-Shits,Mel'nikov,Dem'yanets,Skunman,Chaban
, p. 31 - 37 (2001)
Crystals of Li2TiGeO5 were obtained by solution-melt crystallization, and those of Na2TiGeO5 were grown from a melt by pulling. The crystals are isostructural with the natisite mineral Na2TiSiO5. The crystal structure of Li2{TiOGeO4} was refined by X-ray diffraction analysis (a four-circle diffractometer, 2θ/θ scan mode, MoKα radiation, θmax = 50°). The unit cell parameters are a = 6.614(4) A and c = 4.435(4) A; space group P4/nmm, Z=2, ρcalcd = 3.67 g/cm3, R = 0.031, s = 1.128, wR(F2) = 0.071 (548 reflections with I≥2σI). The ionic conduction in both crystals was found to be anisotropic in the temperature range 250-600°C. At 400°C, the conductivity values are 10-4 to 10-5 S/cm along the a axis and 10-6 to 10-8 (for Na2TiGeO5) and 10-7 to 10-9 S/cm (for Li2TiGeO5) along the c axis.
Preparation of barium titanate films at 55 °C by an electrochemical method
Bendale,Venigalla,Ambrose,Verink Jr.,Adair
, p. 2619 - 2627 (1993)
Work by previous investigators has shown that BaTiO3 films can be synthesized from solution over temperature ranges from 80 °C to greater than 200 °C. In the present work, electrically insulating crystalline films of BaTiO3 have been electrochemically deposited on titanium substrates at temperatures as low as 55 °C. Auger spectroscopic analyses with depth profiling indicate that a titanium oxide layer whose thickness is governed by current density acts as a precursor to BaTiO3. Formation of BaTiO3 is found to be favored only in highly alkaline solutions. This is consistent with the phase stability reported for the Ba-Ti-CO2-H2O system at 25 °C. Lower processing temperatures (55 °C) favor the formation of thick, electrically resistive, and well-crystallized BaTiO3 films, apparently due to increased oxygen solubility in the electrolyte solution. Films produced at 100 °C are much thinner and are electrically conductive due to fissures and pores in their microstructure. Initial studies on the effect of current density indicate the formation of thinner and porous films with thicker titanium oxide intermediate layers.
Grikit, I. A.,Kozhevnikova, A. S.,Dotsenko, S. N.,Rys'eva, Yu. I.
, (1989)
Microstructural and mechanical properties of oxide dispersion strengthened iron aluminides produced by mechanical milling and hot extrusion
Bakshi, S. R.,Chandrasekhar, S. B.,Durga, P. V.,Prasad, K. Satya,Reddy, A. V.,Vijay, R.
, (2020)
Yttria dispersed Fe3Al alloy with a nominal composition of Fe–13Al–5Cr-0.18Ti-0.35 Y2O3 was produced by high energy ball milling followed by hot extrusion. The extruded and heat treated ODS Fe3Al exhibited both elongated and fine equi-axed grain structure in longitudinal direction, whereas, equi-axed grain structure was observed in transverse direction. Even though, both prealloyed as well as milled powder showed only FeAl phase, D03 structured Fe3Al along with Y3Al5O12 and TiO phases existed in ODS Fe3Al. Presence of fine (7–25 nm corresponding to Y3Al5O12) and coarse (>25 nm, TiO) particles were observed in ODS Fe3Al. The material exhibited yield and ultimate tensile strengths of 1104 and 1308 MPa with 8% elongation. The improved strength and elongation are due to the presence of dispersoids and fine grained structure.
OMS, OM(η2-SO), and OM(η2-SO) (η2-SO2) molecules (M = Ti, Zr, Hf): Infrared spectra and density functional calculations
Liu, Xing,Wang, Xuefeng,Wang, Qiang,Andrews, Lester
, p. 7415 - 7424 (2012/07/28)
Infrared spectra of the matrix isolated OMS, OM(η2-SO), and OM(η2-SO)(η2-SO2) (M = Ti, Zr, Hf) molecules were observed following laser-ablated metal atom reactions with SO2 during condensation in soli
