Structure, thermal elongation coefficient, and conductivity of Y1 ? xCaxCr1 ? yMeyO3 (Me = Mg, Cu) in air are studied at 100–1000°C. Electrochemical activity of electrodes made of most conducting compositions Y1 ? xCaxCr1 ? yMeyO3 (Me = Mg, Cu), contacting solid electrolyte 0.9ZrO2 + 0.1Y2O3, is studied over a wide range of polarizations, in air, at 700–900°C. 相似文献
The electrochemical potentials of seven redox transitions for green forms and eight redox transitions for blue forms of neutral
octa-tert-butylsubstituted diphthalocyanine cornplexes of lanthanides Pct2Ln (Ln=Pr, Sm, Dy, and Lu) in solutions were measured by cyclic voltammetry and rotating disc electrode techniques. The spectroelectrochemical
investigation of the products of two-electron oxidation and reduction of the green form of Pct2Lu was performed. The frontier molecular orbitals, total charge densities, total spin densities, electrostatic potentials,
and heats of ion formation for (Pc2Y)m+,n− (m=0, 1, 2 and 3;n=1, 2, 3 and 4), which can model the products of the redox transitions of the diphthalocyanines under study, were calculated
using the semiempirical ZINDO/1 method. The calculations for (Pc2Y)m+,n− and absorption spectra show that the electron changes in all redox transitions of the green forms of Pct2Ln are mainly localized on the ligands.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya No. 12, pp. 2149–2156, December, 1997. 相似文献
In this study, GaAs metal–oxide–semiconductor (MOS) capacitors using Y‐incorporated TaON as gate dielectric have been investigated. Experimental results show that the sample with a Y/(Y + Ta) atomic ratio of 27.6% exhibits the best device characteristics: high k value (22.9), low interfacestate density (9.0 × 1011 cm–2 eV–1), small flatband voltage (1.05 V), small frequency dispersion and low gate leakage current (1.3 × 10–5A/cm2 at Vfb + 1 V). These merits should be attributed to the complementary properties of Y2O3 and Ta2O5:Y can effectively passivate the large amount of oxygen vacancies in Ta2O5, while the positively‐charged oxygen vacancies in Ta2O5 are capable of neutralizing the effects of the negative oxide charges in Y2O3. This work demonstrates that an appropriate doping of Y content in TaON gate dielectric can effectively improve the electrical performance for GaAs MOS devices.
Capacitance–voltage characteristic of the GaAs MOS capacitor with TaYON gate dielectric (Y content = 27.6%) proposed in this work with the cross sectional structure and dielectric surface morphology as insets. 相似文献
This study presents a new synthetic method for fabricating yolk@shell‐structured barium magnesium silicate (BMS) particles through a template‐engaged solid‐state reaction. First, as the core template, (BaMg)CO3 spherical particles were prepared based on the coprecipitation of Ba2+ and Mg2+. These core particles were then uniformly shelled with silica (SiO2) by using CTAB as the structure‐directing template to form (BaMg)CO3@SiO2 particles with a core@shell structure. The (BaMg)CO3@SiO2 particles were then converted to yolk@shell barium magnesium silicate (BMS) particles by an interfacial solid‐state reaction between the (BaMg)CO3 (core) and the SiO2 (shell) at 750 °C. During this interfacial solid‐state reaction, Kirkendall diffusion contributed to the formation of yolk@shell BMS particles. Thus, the synthetic temperature for the (BaMg)SiO4:Eu3+ phosphor is significantly reduced from 1200 °C with the conventional method to 750 °C with the proposed method. In addition, the photoluminescence intensity of the yolk@shell (BaMg)SiO4:Eu3+phosphor was found to be 9.8 times higher than that of the conventional (BaMg)SiO4:Eu3+ phosphor. The higher absorption of excitation light by the structure of the yolk@shell phosphor is induced by multiple light‐reflection and ‐scattering events in the interstitial void between the yolk and the shell. When preparing the yolk@shell (BaMg)SiO4:Eu3+ phosphor, a hydrogen environment for the solid‐state reaction results in higher photoluminescence efficiency than nitrogen and air environments. The proposed synthetic method can be easily extended to the synthesis of other yolk@shell multicomponent metal silicates. 相似文献