Phase Transition and Electrical Properties of Ba0.8Sr0.2TiO3: Comparison of Different Preparation Techniques

2017 ◽  
Vol 866 ◽  
pp. 287-290
Author(s):  
Thanawat Kytae ◽  
Krit Sutjarittangtham ◽  
Theerapol Thurakitseree ◽  
Wilaiwan Leenakul
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Electrical Properties ◽  
Molten Salt ◽  
Preparation Technique ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lcr Meter ◽  
Preparation Techniques ◽  
Scanning Electron

This research studied the effect of the different preparation technique on phase transition and electrical properties of Ba0.8Sr0.2TiO3. The samples compared 3 preparation technique, there are conventional mix-oxide, molten-salt and seed-induced method. The samples prepared by molten-salt calcined at 800 °C, the samples prepared by conventional mix-oxide and seed-induced method was calcined at 1200 °C for 3 h. All of samples sintered at 1400 °C for 3 h. The phase formation and morphology of samples were characterized via X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The dielectric properties of the samples were measurement by LCR-meter.

Preparation and Properties of CCTO-BCTO Ceramics with Ultrahigh Dielectric Constant

2013 ◽  
Vol 760-762 ◽  
pp. 705-708
Author(s):  
La Chen ◽  
Wei Li ◽  
Zhao Xian Xiong ◽  
Chun Xiao Song ◽  
Hong Qiu
Keyword(s):  
Electron Microscopy ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
X Ray Diffraction ◽  
Optimum Amount ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Impedance Characteristics ◽  
Lcr Meter ◽  
Scanning Electron

Ceramics of (1-x)CaCu3Ti4O12-xBi2/3Cu3Ti4O12, i.e., CCTO-BCTO, with x=0, 0.01, 0.1 and 0.25, respectively, were prepared via the conventional solid-state reaction. The phase structure of the ceramics was identified by X-ray diffraction. The microstructure of the sample was observed with scanning electron microscopy. Dielectric properties and impedance spectroscopy were measured using a LCR Meter, in which 0.9CCTO-0.1BCTO displayed highest dielectric constant (584108) and lowest dielectric loss (0.42) at 1kHz among the four kinds of specimens. Based on series of experimental results, an optimum amount of x was able to improve the dielectric properties of CCTO-BCTO, through adjusting the impedance characteristics of the grain and grain boundary.

scholarly journals Effects of annealing parameters on phase, structure and thermochromic properties of VO2 (M) derived from nanostructured VO2(B)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamdi Muhyuddin Barra ◽  
Soo Kien Chen ◽  
Nizam Tamchek ◽  
Zainal Abidin Talib ◽  
Oon Jew Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Different Temperatures ◽  
Thermochromic Properties ◽  
Scanning Electron

Abstract Synthesis of thermochromic VO2 (M) was successfully done by annealing hydrothermally-prepared VO2 (B) at different temperatures and times. Conversion of the metastable VO2 (B) to the thermochromic VO2 polymorph was studied using thermogravimetric analyzer (TGA) under N2 atmosphere. Moreover, the phase and morphology of the synthesized samples were studied using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. Accordingly, the XRD scans of all the annealed samples exhibited the presence of monoclinic VO2 (M), while the FE-SEM images of the samples showed the formation of nanorods and nanospheres, particularly those heated at high temperatures (650 °C and 700 °C). Meanwhile, differential scanning calorimetry (DSC) was used to measure the phase transition temperature (τc), hysteresis, and enthalpy of the prepared VO2. Based on these results, all samples displayed a τc of about 66 °C. However, the hysteresis was high for the samples annealed at lower temperatures (550 °C and 600 °C), while the enthalpy was very low for samples heated at lower annealing time (1.5 h and 1 h). These findings showed that crystallinity and nanostructure formation affected the thermochromic properties of the samples. In particular, the sample annealed at 650 °C showed better crystallinity and improved thermochromic behavior.

scholarly journals Preparation and Properties of Thick Film Resistors Containing Cadmium Glasses and Cadmium Oxide

1980 ◽  
Vol 7 (1-3) ◽  
pp. 29-33
Author(s):  
R. Kužel ◽  
J. Broukal
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Differential Thermal Analysis ◽  
Electrical Properties ◽  
Cadmium Oxide ◽  
X Ray Diffraction ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
Scanning Electron

The electrical properties of resistors comprising finely divided CdO and cadmium glass, were investigated. The change in a temperature coefficient of resistance from about −500 ppm/℃ to +70 ppm/℃ was realized by addition of a further component to the resistor paste. Differential thermal analysis, X-ray diffraction analysis and scanning electron microscopy were used for studying crystalline phases in glass containing CdO.

A Study of Substitution the Element of (La+3) on the Structural and Electrical Properties of the Compound Ferrite (𝐂𝐨𝟎.𝟐𝟓𝑵𝒊𝟎.𝟐𝟓𝐙𝐧𝟎.𝟓𝐋𝐚𝐱𝐅𝐞𝟐−𝐱𝐎𝟒)

2021 ◽  
Vol 19 (3) ◽  
pp. 56-61
Author(s):  
Bilal Ahmed Omar ◽  
Rabab Shakour Ali
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Spontaneous Combustion ◽  
Chemical Formula ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural And Electrical Properties ◽  
Scanning Electron

The ferritic nanocomposite which prepared has the chemical formula of (Co0.25𝑁𝑖0.25Zn0.5LaxFe2−xO4), for different values of (X= 0, 0. 25, 0. 5, 0. 75), by using the spontaneous combustion-gel method, where calcination had been at temperature of (700˚C) for two hours; then studied the structural properties of the resulting ferrite via X-Ray diffraction (XRD), and Scanning Electron Microscopy (SEM) The results denote that the ferrite has a unique phase with a spinal-shaped crystal structure and a granular size are (23-36) nm, with increase in lattice constant of decrease in porosity, and electrical properties were also take in to consideration, like value of dielectric constant, the loss coefficient also observed via increase the frequency. The alternating electrical conductivity (σa.c) increases with increasing frequency.

Effect of heat treatment time and temperature on the properties of YBa2Cu3O7−x

1989 ◽  
Vol 4 (5) ◽  
pp. 1093-1098 ◽  
Author(s):  
Ira Bloom ◽  
B. S. Tani ◽  
M. C. Hash ◽  
Donglu Shi ◽  
M. A. Patel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrical Properties ◽  
Treatment Time ◽  
The Other ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Rich Material ◽  
Scanning Electron

Two YBa2Cu3O7−x powders were investigated: one was nearly stoichiometric, and the other, CuO-rich. After being sintered at 950 °C, samples from both powders were heat-treated in oxygen at 845, 860, and 910 °C for up to 10 days. The samples were characterized by differential thermal analysis, x-ray diffraction, optical and scanning electron microscopy, iodometric titrations, and measurement of their superconducting properties (electrical resistivity, critical temperature, and critical current density). The electrical properties of the nearly stoichiometric material improved with time at all temperatures. On the other hand, the electrical properties of the CuO-rich material deteriorated with temperature, possibly owing to problems associated with grain growth at 910 °C.

Effect of Cooling Rates on the Solidification and Microstructure of Rapidly Solidified Mg70.8Zn28Nd1.2 Quasicrystal Alloy

2017 ◽  
Vol 898 ◽  
pp. 246-253
Author(s):  
Xing Jing Ge ◽  
Xin Ying Teng ◽  
Shu Min Xu ◽  
Jin Yang Zhang
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Thermal Analysis ◽  
Energy Dispersive Spectrometer ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Cooling Rates ◽  
X Ray ◽  
Rapidly Solidified ◽  
Scanning Electron

The influence of cooling rates on the solidification and microstructure of rapidly solidified quasicrystal alloy Mg70.8Zn28Nd1.2(at.%) was investigated. The microstructure, phase constitution, phase transition and phase structure of the alloys were examined by means of scanning electron microscopy, x-ray diffraction, energy dispersive spectrometer, differential scanning calorimetry. The experimental results showed that the phase composition of as-cast Mg70.8Zn28Nd1.2 alloy includes quasicrystal I-phase and Mg7Zn3 phase. For the rapidly solidified alloy ribbons, when the speed is not higher than 400 r/min, the microstructure includes I-phase, Mg7Zn3 phase and α-Mg phase. When the speed is at the range of 400-2000r/min, the Mg7Zn3 phase disappears and only quasicrystal with α-Mg phase exist. With the increase of cooling rate, the grain size decreases and there are a large number of microcrystals in the microstructure. When the speed reaches higher than 2500 r/min, amorphous phase appeared. Differential thermal analysis showed that quasicrystal exist at about 340°C.

Influences of Sintering Temperature on Microstructure and Electrical Properties of TiO2 Varistor Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 317-319
Author(s):  
Yan Yan Chen ◽  
Ming Zou ◽  
Yuan Wang ◽  
Yun Zhang
Keyword(s):  
Crystal Structure ◽  
Electrical Properties ◽  
Sintering Temperature ◽  
Nonlinear Coefficient ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fine Microstructure ◽  
Lcr Meter ◽  
Frequency Dependences ◽  
Scanning Electron

Influences of sintering temperature on microstructure and electrical properties of TiO2 varistor ceramics were investigated. Morphologies of TiO2 ceramics samples were characterized using scanning electron microscope. The phase composition and crystal structure were researched by X-ray diffraction. The frequency dependences of the samples capacitance were determined using LCR meter, the varistor voltage V1mA and nonlinear coefficient α were discussed by experimental method. The results showed that TiO2 ceramics sintered at 1350°C for 2 h possesses fine microstructure and optimal electrical properties. However, the electrical properties of samples will deteriorate as excessive sintering temperature.

Study of 4.5%mol Y2O3-Doped ZrO2 with Submicrometer Grain Size

2014 ◽  
Vol 805 ◽  
pp. 570-575
Author(s):  
Eleomar Lena ◽  
Adriana Scoton Antonio Chinelatto ◽  
Adilson Luiz Chinelatto
Keyword(s):  
Electron Microscopy ◽  
Activation Energy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Electrical Properties ◽  
Pechini Method ◽  
Oxygen Flow ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The aim of this study was to obtain 4.5%mol Y2O3-doped ZrO2dense with submicrometer grain size and studying the effects of using oxygen flow during calcination in the electrical properties of bodies sintered. The powders were synthesized by the Pechini method. After synthesis, the resins were dried and the calcinations were performed in air and in oxygen flow at 600°C for 2 h. The powders were pressed with 1600 MPa and sintered by Two Step Sintering (TSS) at 1500°C / 5 min and 1200°C, 1300oC, 1400°C, remaining at these temperatures for 2 and 10 hours. The sinterized samples were characterized by X-ray diffraction, apparent density, scanning electron microscopy and impedance spectroscopy. The apparent densities were greater than 94% for all conditions of calcination and sintering. The value of the activation energy was 0.7eV for the grain and 0.9 eV for the grain boundaries.

Preparation of Alumina Fibers by Needle-Less Electrospinning

2017 ◽  
Vol 891 ◽  
pp. 478-482
Author(s):  
Erika Mudra ◽  
Magdalena Streckova ◽  
Alexandra Kovalcikova ◽  
Martin Šebek ◽  
Vladimír Girman ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electrospun Fibers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Alumina Fibers ◽  
Scanning Electron

In this study the needle-less electrospinning by means of “NanospiderTM“ (ELMARCO) as technology for the preparation of fine α-Al2O3 fibers with diameters of 0.5 - 1.5 µm is presented. The fabrication consists of three steps: i) preparation of spinning solution, ii) electrospinning of the prepared solution and collection of the composite fibers, iii) calcination of the composite precursor fibers. The electrospun fibers were prepared from polyacrylonitrile/N,N-dimethylformamide (PAN/DMF) polymer solution and Al(NO3)3.9H2O in ratio 1/10/1. Thereafter, the precursor fibers were calcined in the furnace at 900, 1100 and 1200 °C with a rate of 5 °C/min in air. The formation of crystalline phases, surface morphology and diameters of metastable and final alumina fibers were characterized using thermogravimetric analysis, X-ray diffraction analysis, the scanning electron microscopy and transmission electron microscopy. The precursor PAN/Al(NO3)3 fibers were amorphous. The thermal treatment leads to the phase transition from γ-Al2O3 to α-Al2O3 accompanied by removing of polyacrylonitrile (PAN). The fine porous microfibers composed of pure α-Al2O3 phase were prepared after calcinations at 1200 °C.

Influence of La2O3 on the Electrical Properties of Dense SnO2 Electrodes

2011 ◽  
Vol 675-677 ◽  
pp. 171-174 ◽  
Author(s):  
Qing Wei Wang ◽  
Hong Zhi Wang ◽  
Wei Ning
Keyword(s):  
Electron Microscopy ◽  
Electrical Properties ◽  
Room Temperature ◽  
Tin Dioxide ◽  
Deposition Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sno2 Powder ◽  
Traditional Ceramics ◽  
Scanning Electron

We prepared La2O3 doped SnO2 powder by a co-deposition method and used the doped material to manufacture tin dioxide electrodes by traditional ceramics methods.. The results showed that La2O3 led to an obvious decrease in electrical resistivity at room temperature but it had little influence at temperatures higher than 600 °C. The samples were characterized by X-ray diffraction and section scanning electron microscopy. We found that La2O3 increased the rate of tin dioxide crystal growth. At La2O3 concentrations as high as 1 wt%, a new La2Sn2O7 phase was present and this phase plays an important role in improving the electrical properties of the La2O3-doped SnO2.

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