Addition Of SnO2 Research Articles

磁性材料の化学 ＳｎＯ２置換による低損失ＭｎＺｎフェライト

The effect of chemical composition and firing conditions on the core loss characteristics of MnZn ferrite has been studied with special reference to the factors of core loss. It was found that hysteresis and eddy current losses comprise most of the core loss for MnZn ferrite used at 100kHz. Especially, the eddy current loss remarkably increased with increasing the frequency in comparison with hysteresis loss. On the basis of the fact that the eddy current loss bears a linear relationship to the electrical resistivity, an experimented addition of SnO2 to MnZn ferrite has been tried to improve the electrical resistivity. As a result, MnZn ferrite with low power loss has been successfully developed.

Experimental studies and space charge mechanism for the conductivity/mobility enhancement due to SnO2 dispersion in Ag+ ion conducting borate glass

The enhancement in ionic conductivity of a Ag+ ion conducting borate glass of molar % composition 55.5 Agl-22.25 Ag20-22.25 B2O3 is reported with the dispersion of SnO2. X-ray diffraction (XRD), i.r. and optical microscopy reveals that the SnO2 addition yields a dispersed phase material and not a new glass. The material is essentially a Ag+ ion conducting (Agl+Ag2O+B2O3) glass in which SnO2 is dispersed. The direct measurement of mobility of the mobile ions reveals that the enhancement in conductivity is controlled by the enhancement in mobility. A space charge model based on the mechanism of adsorption-desorption of mobile ions near/at the interface in the space charge region creating a certain type of mobile ion concentration gradient is introduced to explain the results.

Ion storage properties of CeO2 and mixed CeO2/SnO2 coatings

Ion storage CeO2 and CeO2/SnO2 coatings were prepared by the sol-gel dip-coating method using an aqueous-based process. The influence of added SnO2 in the CeO2 oxide coatings on the inserted/extracted charge was determined by chronocoulometric measurements. It was found that for 60 nm thick film, the inserted/extracted charge was twice (Q=10 mC cm−2) as large for films containing 17 mol% SnO2, if compared to pure CeO2. The effect of the addition of SnO2 to the mixed oxide coatings on their optical properties and structural characteristics was studied.

The effects of SnO2 addition on the growth of Y2BaCuO5 and YBa2Cu3O7- delta phases in the Y-Ba-Cu-O system

With YBa2Cu3Sn0.1O7- delta and Y2BaCu1.8Sn0.1O5+ delta specimens, the effect of SnO2 addition on the 211 phase growth is investigated. The addition of SnO2 is considered to make the nucleation of the 211 phase occur favourably. In order to study the effect of SnO2 addition on 123 phase growth in the Y-Ba-Cu-O system, a 0.1 SnO2-added 123+Sn compact is coupled with the SnO2-free 123 compact(s). The 123 phase forms in the surface region of the 123+0.1 Sn compact and grows toward the interior of this compact and toward the SnO2-free 123 compact(s). It is considered that the addition of SnO2 and faster cooling in the surface region than in the inner region of the sample make the nucleation of the 123 phase occur favourably in the surface region of the 123+0.1 Sn compact.

Morphology of (Ru-Ti-Sn) mixed-oxide coatings

Noble-metal-oxide-based coatings have successfully replaced many of the conventional anode materials in industrial electrochemical processes. The performance characteristics of these mixed-oxide electrodes have been found to be improved by the inclusion of non-noble-metal-oxide components. Of these, the addition of SnO2 to RuO2-TiO2 has attracted much attention. In the present paper, the morphology change imparted by gradual replacement of TiO2 by SnO2 from the RuO2-TiO2 (30/70) coatings is reported. Scanning electron microscopic examination and porosity determination reveal that significant modifications take place in the surface structure, and the surface layer tends to become compact at SnO2 concentration above 30 mol % SnO2.

Some experimental data on thin mixed films of silicon monoxide/germanium dioxide

Abstract Mixed amorphous films are of interest as electronic materials and materials based on silicon monoxide are under substantial investigation. Comparisons are made between SiO/GeO2 and SiO/SnO2 films. In general the electrical properties of the two series are similar but the optical properties demonstrate significant differences. The effect of SnO2 addition has a greater effect on paramagnetic resonance than adding GeO2.

X-Ray absorption study on the local structures of fine particles of α-Fe2O3–SnO2gas sensors

X-Ray absorption spectra (EXAFS) have been recorded of the local structure around iron and tin in fine powdery α-Fe2O3–SnO2, prepared by thermal decomposition of coprecipitates from aqueous iron(III) sulfate and tin(IV) chloride solutions at pH 8. Tin atoms are substituted for iron atoms in the corundum structure of α-Fe2O3 below 15 mol% SnO2 which is the limit of dissolution. Further addition of SnO2 destabilises the system such that SnO2enters the lattice as a substitutional defect. At > 50 mol%, SnO2 forms a mixture of a rutile SnO2 phase and an SnO2 phase dissolved in α-Fe2O3. The Fe2O3(33 mol%)–SnO2(67 mol%) structure consists of rutile SnO2 and an irregular iron oxide phase. The high sensor sensitivity for CH4 is intimately correlated with the amount of SnO2 dissolved in α-Fe2O3.

The role of tin in Li/Sn/MgO catalysts for the oxidative coupling of methane

The addition of SnO2 to the Li/MgO catalyst system has been found to stabilize its catalytic activity for the oxidative coupling of methane, and, when a large amount of SnO2 is added, a new phase, Li2Mg3SnO6 is identified; pure Li2Mg3SnO6 is also an active and selective catalyst for the oxidative coupling of methane, and in contrast with Li/MgO, it retains lithium under reaction conditions, thereby suppressing deactivation.

Enhancement of critical current density in TlBaCaCuO type superconductors by the addition of SnO2

The addition of SnO2 to a mixture of Tl2O3 and Ba2Ca3Cu3O7 was found to enhance the critical current density (Jc) of the subsequently fabricated superconductor. Without SnO2, the Jc of the silver-sheathed superconductor of optimal thallium content was 7.4 to 7.6×103 A/cm2 at 77 K and zero external magnetic field. With the addition of 0.1 formula-weight of SnO2 per formula-weight of the superconductor, its Jc was raised to 1.1 to 1.2×104 A/cm2 under the same conditions. XRD data show that the ratio of 2223-phase can be greatly increased by the addition of SnO2 and rapid quenching of the hot pellet in liquid nitrogen. However, SEM and EDAX analyses show that the superconducting phase in the ceramic sample does not contain Sn and suggest that the role of SnO2 is to stabilize the 2223-phase and improve intergranular or interfacial contact.

Selective oxidation of methane and ethane over Li +-MgO-Cl − catalysts promoted with metal oxides

The addition of SnO 2, La 2O 3, Nd 2O 3 or Dy 2O 3 to a Li +-MgO-Cl − catalyst significantly improves the activity for the oxidative dehydrogenation of ethane, while maintaining a high selectivity for ethylene. Over a Dy 2O 3/Li +-MgO-Cl − catalyst 75% conversion of ethane with 76% selectivity to ethene was achieved at 570 °C after 25 h on stream. This catalyst also is reasonably active and selective for the oxidative coupling of methane at 600 °C.

Effect of oxide additions on the properties of plasma-sprayed Y-Ba-Cu-O coatings

Plasma-spraying is a potential technique for forming flexible tapes from the brittle highT c oxides. It is possible to obtain superconducting YBa2Cu3O x coatings by a suitable heat-treatment after spraying. In an effort to improve the critical current densities of the coatings, the effect of additions of Ag2O, Bi2O3 and SnO2 to the YBa2Cu3O x powder used for spraying was studied. The maximumJ c value of 75 A/cm2 was obtained for the sample doped with 5% SnO2.

Ｂａ２Ｔｉ９Ｏ２０の組織および誘電特性に及ぼすＳｎＯ２添加の影響

Ｂａ２Ｔｉ９Ｏ２０の組織および誘電特性に及ぼすＳｎＯ２添加の影響

Factors Affecting the Formation of Ba2Ti9O20

The phase development sequence based on a composition equivalent to Ba2Ti9O20 during heating is found to be in the following order: BaTi5O11 > BaTi4O9 > Ba2Ti9O20. The lowest rate of formation of Ba2Ti9O20 is caused by its high surface energy and interface energy, which result in a low nucleation rate. The existence of BaTi5O11 in calcined powder helps to form Ba2Ti9O20 in sintered compacts. The effect of BaTi5O11 on Ba2Ti9O20 formation can be explained by their similar oxygen packing and by reduced volume change during transformation. The amount of BaTi5O11 formed during heating depends greatly on the compositional homogeneity of powders. The addition of SnO2 aids the formation of Ba2Ti9O20 by reduced strain energy at transformation and reduced surface energy.

Effect of additions of TiO2, SnO2, and Al2O3on electrical properties of tetragonal zirconia

The effect of additions of TiO2 and SnO2 on the tetragonal phase of the ZrO2–Y2O3 system has been investigated using complex impedance, X-ray, and transmission electron microscopy measurements. Neither addition acts to stabilize the tetragonal phase and SnO2 increases the specific grain boundary resistance by a factor of 3. Additions of Al2O3 improve the specific grain boundary conductivity of GPR (general purpose reagent) grade material to a level comparable to that of commercially available grades of tetragonal zirconia.MST/558

Effect of the Addition of Multivalent Ions and the Irradiation of U. V. Rays on Colour Development in Silver-containing Glasses

It is known that the addition of SnO, Sb2O3, Fe2O3 and CeO2 etc., the oxides of multivalent elements, promote the development, and stabilization of the colloidal colours obtained by reheating the glasses containing Au, Ag, and Cu. In order to know the mechanism of the function of so called thermoreducing agents, or sesitizers, in developing colours a series of experiments has been carried out taking Ag-glass as an example.The composition of base glass was Na2O 18.0, CaO 8.5, Al2O3 1.5, and SiO2 72.0% by weight, and to which 0.025 gram atom of Ag2O, and 1 or 4 gram atoms of 11 thermoreducing agents, i.e., TiO2, V2O5, Cr2O3, MnO2, FeC2O4⋅2H2O, CoO, NiO, SnO, Sb2O3, Ce2 (C2O4)3, UO2(NO3)2 were added.The 20 glass samples prepared from the different combinations of sensitizers given above were subjected to the combinations of following heat treatments:1) Holding for 10 minutes at 650°C followed, respectively, by cooling to 400°C in 2 hours at constant rate and then quenching to ordinary temperature.2) Irradiation by ultraviolet rays.3) Preheating at 800°C for 10 minutes.The spectral transmission between 250 and 750mμ of the specimens which have developed colours by applying the combined treatments of above three types were measured, and the results were compared with the transmission of those containing no sensitizer and have passed through the exactly the same pretreatments.Within the scope of the present experiments it has been shown that the ions of Cr, Co, Sn act effectively in the colour development by heat treatment, while those of Cr, Fe, Sn, Sb, Ce are effective in developing by ultraviolet irradiation.Considering that these effects may be ascribed to the increase of the concentration of atomic silver, Ag°, during the heat treament, where the constants of the equilibria, such asAg°→←Ag+M+→←M2+, in which M is a multivalent element, are highly temperature dependent, the author was able to explain satisfactory the function of the thermoreducing agents, or sensitizers, by the difference of the temperature dependency of the equilibria.

Dielectric Losses of Some Simple Ternary Silicate Glasses

The effect on alkali ion mobility of compositional changes in simple glasses was investigated by observing the dielectric loss behavior in a number of ternary glass systems, formed by adding increasing amounts of various third components to potassia‐silica and soda‐silica base glasses. Oxides of barium, strontium, calcium, cadmium, lead, magnesium, zinc, aluminum, boron, tin, zirconium, titanium, and silicon were introduced. Tan δ values were determined at room temperature and at a frequency of 1 kc. per second. Na+ ion mobility was found to be profoundly influenced by the type and amount of third component present. RO oxides decreased tan δ by amounts which appear to bear some relation to the size of the cation introduced. Tan δ curves for the MgO and ZnO series were unique in that each was characterized by a pronounced minimum and maximum. Curves for SnO2, Al2O3, and ZrO2 additions passed through a minimum and in the latter two cases rose to tan δ values greater than that of the base glass itself. Curves for the series containing B2O3 and TiO2 continued to lower values throughout the range of compositions studied. The characteristic shapes of the loss curves are discussed with reference to the roles assumed by the introduced cations.

The Ternary Systems BaO–TiO2–SnO2 and BaO‐TiO2‐ZrO2

An investigation of the ternary systems BaO‐TiO2‐SnO2 and BaO‐TiO2‐ZrO2 led to the discovery of two new compounds belonging to the system BaO‐TiO2. These compounds, Ba2Ti9‐O20 and Ba2Ti9O20, are stabilized by minute additions of SnO2 or ZrO2. The known compound BaTi2O5 can be obtained only from the molten phase and decomposes below 1300°C. into Ba2Ti5O12 and BaTiO2. In these systems no ternary compounds are found. The ternary phase diagrams can be divided into regions with high and low dielectric losses, which are in accordance with the phase relations. Tables with crystallographic data of the new compounds are included.