Microwave Processing of Sol-Gel Derived Potassium Niobate

1990 ◽  
Vol 180 ◽  
Author(s):  
Z. Fathi ◽  
I. Ahmad ◽  
D.E. Clark
Keyword(s):  
Sol Gel ◽  
Microwave Energy ◽  
Phase Changes ◽  
Conventional Heating ◽  
Potassium Niobate ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Novel Processing ◽  
The Relationship

ABSTRACTMicrowave energy has been used in a novel processing method. The relationship between processing, structure and properties of sol-gel-derived potassium niobate sol as well as thin films has been investigated. A comparison has been established between microwave and conventional heating for drying, calcining and crystallizing sol-gel-derived samples. Structural and phase changes were monitored by thermogravimetric analysis (TGA), differential thermal analysis (DTA) and x-ray diffraction (XRD).

Study of the Phase Formation of Sol-Gel YBa2Cu3O7-x Samples in Flowing Oxygen Atmosphere

2007 ◽  
Vol 546-549 ◽  
pp. 2097-2102
Author(s):  
Ting Luo ◽  
Yi Zhang ◽  
Qing Rong Feng
Keyword(s):  
Room Temperature ◽  
Sol Gel ◽  
Oxygen Atmosphere ◽  
Ambient Atmosphere ◽  
X Ray Diffraction ◽  
X Ray ◽  
Whole Process ◽  
Relationship Of ◽  
The Relationship ◽  
Flowing Oxygen

The relationship of the resistivity versus synthesizing temperature of sol-gel YBa2Cu3O7-x samples, with Tc 91K, was studied while synthesizing in flowing oxygen atmosphere. A set of high temperature -T curves were obtained for the whole process. After four rounds of synthesizing, the resistivity of the sample was =1.00×10-3cm at room temperature. The -T curve of the last round also showed that the orthorhombic to tetragonal phase transformation of the sample occurred around 600oC that is lower than the YBa2Cu3O7-x sample prepared in ambient atmosphere. Other measurements such as X-ray diffraction, SEM measurement, low temperature R-T and M-T measurement were also taken to get more information of these samples.

Properties of SiO2CuOx Films for Nitrogen Dioxide Detection

2013 ◽  
Vol 834-836 ◽  
pp. 112-116 ◽  
Author(s):  
Tatiana Myasoedova ◽  
G.E. Yalovega ◽  
V.V. Petrov ◽  
O.V. Zabluda ◽  
V.A. Shmatko ◽  
...  
Keyword(s):  
Thin Films ◽  
Nitrogen Dioxide ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Technique ◽  
Operating Temperatures

SiOxCuOythin films were prepared by the deposition on to the Si/SiO2substrates from the alcoholic solutions employing the sol-gel technique. The various analytic techniques were applied to characterize structure and properties of the films under study . The both X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) studies showed the presence CuO as well as CuO2phases and formation of a dual-oxide CuSiO3with the average crystallites sizes of 35-50 nm. The conductance of the films was rather sensitive to the presence of 1-20 ppm NO2concentration at the operating temperatures in the range of 20–200◦C.

Study on the Electrolyte Material BaCe1-xYxO3-δ’s Raman Spectra and Electrical Properties for Intermediate-Temperature Solid Oxide Fuel Cells

2011 ◽  
Vol 233-235 ◽  
pp. 2419-2423
Author(s):  
Jin Xia Wang ◽  
Jia Wen Jian ◽  
Yuan Yuan Gu
Keyword(s):  
Oxygen Vacancy ◽  
Solid Oxide Fuel Cells ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Solid Oxide ◽  
Crystal Symmetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Single Perovskite Phase ◽  
The Relationship

In this paper we used sol-gel method for synthesizing Y3+-doped BaCeO3 solid electrolyte BaCe1-xYxO3-δ(x=0.10, 0.15, 0.20, 0.25, 0.30). The samples crystallized in a single perovskite phase by X-ray diffraction analysis after sintering at 1450°C in air for 10h; Raman spectrum measurements indicated that the increasing of Y3+ doped content increased the crystal symmetry and increased the oxygen vacancy content for the samples, all Y3+ ions were doped into the Ce-sites; The electric conductivities of the samples increased with Y content and reach a maximum at x=0.25, then decreased. The relationship between proton conductivity and Y dopant was closely related with oxygen vacancy content, crystal symmetry and the forming of defect association.

Microstructural Development and Properties of (1-x) wt% Ba0.55Sr0.45TiO3-x wt% MgO Bulk Ferroelectrics

2001 ◽  
Vol 699 ◽  
Author(s):  
Costas G. Fountzoulas
Keyword(s):  
Solid State ◽  
Parallel Plate ◽  
Sol Gel ◽  
Microstructural Development ◽  
X Ray Diffraction ◽  
Parallel Plate Capacitor ◽  
X Ray ◽  
Dry Pressing ◽  
The Relationship ◽  
Scanning Electron

AbstractA study was made of the relationship between the microstructure and electrical properties of the bulk ferroelectric composite materials: (100-x) wt% Ba0.55Sr0.45TiO3-x wt% MgO. The ferroelectric composites (x= 40, 60) were fabricated by dry pressing from two powder precursors: 1) Ba0.55Sr0.45TiO3 (BST) calcined in the solid state with sol-gel MgO (Sg-MgO), and 2) hydrothermal BST and MgO calcined in the solid state. The pellets were sintered at 1250, 1350 and 1450°C. The sintered microstructure, chemistry, and phase with crystallinity was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD), respectively. The density and porosity were determined by the Archimedes technique. Dielectric properties of permittivity and loss tangent were characterized by the parallel plate capacitor method.

Impact of Cations Nature of Double Perovskite Ca2BWO6 on Structure and Magnetic Properties

2017 ◽  
Vol 68 (3) ◽  
pp. 504-506
Author(s):  
Ioana A. Gorodea ◽  
Nicoleta Cornei ◽  
Ion Sandu
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Double Perovskite ◽  
Combustion Method ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Perovskite Type Oxide ◽  
The Fourier Transform ◽  
Perovskite Type

The aim of this work is to study the perovskite-type oxide Ca2BWO6 materials, where B = Cr, La and Sm, obtained by the sol�gel citrate-combustion method. The nature of the B-site cations influences the structure and properties of these compound. The synthesis progress was evaluated using X-ray diffraction and the structure of the samples was characterized by the Fourier transform infrared spectroscopy. In our case, the tolerance factor decrease with increasing of the ionic radius B leads to the structural distortion different from the cubic one. The magnetic properties were evaluated by a SQUID magnetometer and they are discussed in relationship with their compositions. From experimental data, it was noticed that all compound are ferromagnetic.

The Capacitive Behavior of Ni0.76Co0.24Ox Xerogels in KOH Solution

2012 ◽  
Vol 608-609 ◽  
pp. 1092-1096
Author(s):  
Jie Cheng ◽  
Xin Jin Tian ◽  
Yue Hua Wen ◽  
Yan Xu ◽  
Han Min Liu ◽  
...  
Keyword(s):  
High Performance ◽  
Electrode Materials ◽  
Sol Gel ◽  
Constant Current ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Capacitive Behavior ◽  
Heat Treated ◽  
A Current

Ni0.76Co0.24Ox xerogels were formed by the sol-gel method followed by heat-treatment in air. The structure and properties of these materials were characterized by using X-ray diffraction, TEM and N2 (77K) adsorption. Electrodes with the xerogels were activated by cyclic voltammetry (CV) and their capacitive performance was evaluated by galvanostatic technique in 7 mol/L KOH solutions. A maximum specific capacitance of 904 F/g was obtained by constant current discharge with a current density of 2.0 mA/cm2 for the Ni0.76Co0.24Ox xerogels heat-treated at 250°C. High performance obtained indicates that these materials are promising electrode materials for supercapacitors.

Interface Structure of Be/HR-1Stainless Steel by Vacuum Diffusion Bonding

2011 ◽  
Vol 314-316 ◽  
pp. 968-971
Author(s):  
Hui Li ◽  
Shang Qi Zhou ◽  
Ji Lan Kong
Keyword(s):  
Stainless Steel ◽  
Diffusion Bonding ◽  
Testing Machine ◽  
Interface Structure ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Composition And Structure ◽  
Material Testing Machine ◽  
The Relationship

Be and HR-I stainless steel with AgCu28 as an interlayer was diffusion bonded by hot pressing，The microstructure，distribution of composition and phase，mechanical properties of the joints were analyzed using scanning electron microscopy(SEM)，scanning auger microspectroy(SAM)，x-ray diffraction(XRD) and material testing machine，and the relationship between composition and structure and properties，and the effect of interlayer materials AgCu28 alloy were also discussed．The results show that good joint can be obtained using AgCu28 alloy as an interlayer material，because it can reduce the mutual diffusion between beryllium and stainless steel elements，the formation of brittle intermetallic compounds between beryllium and stainless steel elements are avoided effectively to improve the diffusion bonding strength and properties．

Kinetics Transformation of Anatase to Rutile Phase for Titanium Dioxide Nanoparticles Prepared by Sol-Gel Method

2013 ◽  
Vol 756 ◽  
pp. 11-15
Author(s):  
Muneer M. Ba-Abbad ◽  
Abdul Amir Hassan Kadhum ◽  
Abu Bakar Mohamad ◽  
Mohd Sobri Takriff ◽  
Kamaruzzaman Sopian ◽  
...  
Keyword(s):  
Activation Energy ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Rutile Phase ◽  
Phase Changes ◽  
Avrami Equation ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Calcination Temperatures

Simple sol-gel route was used to synthesis the TiO2 nanoparticles and examined by X-ray diffraction (XRD). The small particle size and uniform morphology of the TiO2 were found at different calcination temperatures. The kinetic study of phase changes from the anatase to rutile using the X-ray diffraction data with Avrami equation was investigated. The transformation of anatase to rutile was started after 500 °C and above by decreasing of XRD peaks intensity of anatase with rutile increased. The activation energy of the rutile phase was found lower which indicated that uniform shape and morphology of TiO2 nanoparticles. At same time, changes of activation energy value depended on the experimental conditions was observed.

ANALYSIS OF CHARACTERISTICS OF ORDERED MESOPOROUS ASSEMBLED WITH Fe, Bi AND B

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2780-2785
Author(s):  
JIANCHENG ZHANG ◽  
QILIANG NI ◽  
YUE SHEN ◽  
XIAO'AN ZHOU ◽  
SHENGYU JIANG ◽  
...  
Keyword(s):  
Mesoporous Materials ◽  
Sol Gel ◽  
Acid Sites ◽  
Coupling Agents ◽  
X Ray Diffraction ◽  
X Ray ◽  
Specific Saturation Magnetization ◽  
Transmission Electron ◽  
Ordered Mesoporous ◽  
The Relationship

Ordered SiO 2 mesoporous materials called SBA were prepared by hydrothermal or sol-gel method through using the surfactants as the template, such as cetytrimethylammonium bromide or triblock copolymer. SBA assembled with some different elements and compounds, including Fe , Bi , and B or Fe 2 O 3, B 2 O 3 and others by dipping or adding of chelating or coupling agents were prepared to form some composites, which characterized by wide or small angle X-ray diffraction, infrared spectra, N 2 static and kinetic adsorption, high resolution transmission electron microscopy and magnetic intensity instrument, respectively. The assembled α- Fe or α- Fe 2 O 3 under different conditions possessed lower magnetic coercive force (Hc), for instance the latter was about 87-117( Hc –103/4πA*m-1– Os ), but specific saturation magnetization (σ s –A*m2*kg-1) increase by 75.4% as compared with the conventional σ- Fe 2 O 3(1765 Os ) particles. However, the properties of the composites assembled with α- Fe was different from α- Fe 2 O 3 as mentioned-above. And the relationship between σ s or Os and structure for the assembled systems was discussed. After introduced B and Bi to the mesoporous materials, the composites showed not only existence of Brφnsted acid sites for B , but also improvement of the hydrothermal stability and enhance of the long–range order magnitude.

scholarly journals Structure and Electrochemical Impedance of LiNi\(_{x}\)Mn\(_{2 - x}\)O\(_{4}\)

2017 ◽  
Vol 26 (4) ◽  
pp. 361
Author(s):  
Ta Anh Tan ◽  
Nguyen Si Hieu ◽  
Le Ha Chi ◽  
Dang Tran Chien ◽  
Le Dinh Trong ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Ni Substitution ◽  
Eis Measurements ◽  
The Relationship ◽  
Substitution Content ◽  
Ac Conduction

Ni-substitution spinel LiNixMn2−xO4 (x = 0, 0.1, 0.2) materials were synthesized by the sol--gel method. The structure and  morphology of the samples were characterized by the X-ray diffraction (XRD)  and the scanning electron microscopy. The ac conduction of the materials was  investigated by electrochemical impedance spectroscopy (EIS) measurements.  The refinement results showed that the substitution of Ni decreased the  lattice constant and Mn--O distance, while increased Li--O bond length and  16c octahedral volume. The EIS results confirmed the decrease of  conductivity with increasing Ni substitution content. Based on XRD and EIS  results, the relationship between the crystal structure and electrochemical  behavior of the materials was discussed and explained.

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