Effects of CuO on the Preparation, Microstructure and Dielectric Response of CaCu3Ti4O12

2008 ◽  
Vol 368-372 ◽  
pp. 121-122
Author(s):  
Jian Fang Qiao ◽  
Dan Dan Qin ◽  
Li Guan ◽  
Hai Long Wang ◽  
Rui Zhang
Keyword(s):  
Solid State ◽  
Grain Growth ◽  
Barrier Layer ◽  
Solid State Reaction ◽  
Dielectric Response ◽  
Second Step ◽  
Sintering Process ◽  
Ceramic Capacitor ◽  
Inhomogeneous Microstructure ◽  
Maximum Permittivity

CaCu3Ti4O12 (CCTO) barrier layer ceramic capacitor was prepared by a two-step sintering process. The CCTO powders were pre-synthesized at 900oC by solid-state reaction and the effects of the amount of CuO on the formation of the CCTO powders were investigated. The CCTO ceramics were prepared by the second-step sintering. It was found that the abnormal grain growth and inhomogeneous microstructure are controlled by the amount of excessive CuO. The optimized CuO content in the composites is ~14 wt%. The maximum permittivity is 115,000 (1 kHz, 210oC).

scholarly journals Synthesis of Cubic Phase-Co Microspheres by Mechanical Solid-State Reaction-Thermal Decomposition and Research on Its Growth Kinetics

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Ying Deng ◽  
Yanhua Zhang ◽  
Lingling Peng ◽  
Xiaolong Jing ◽  
Hui Chen
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Grain Growth ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Energy Content ◽  
Industrial Applications ◽  
Cubic Phase ◽  
Oxalate Precursor ◽  
Cobalt Oxalate

Cubic phase cobalt (Co), which can be used as a key component for composite materials given its excellent ductility and internal structure, is not easy to obtain at room temperature. In this study, oxalic acid and cobalt nitrate are used as raw materials to synthesize the cobalt oxalate precursor, which has a stable structure with a five-membered chelate ring. Cobalt oxalate microspheres, having a high internal energy content, were prepared by using mechanical solid-state reaction in the presence of a surfactant, which can produce spherical micelles. The thermal decomposition of the precursor was carried out by maintaining it in a nitrogen atmosphere at 450°C for 3 h. At the end of the procedure, 100 nm cubic phase-Co microspheres, stable at room temperature, were obtained. Isothermal and nonisothermal kinetic mechanisms of cobalt grain growth were investigated. The cubic-Co grain growth activation energy, Q, was calculated in this study to be 71.47 kJ/mol. The required reaction temperature was low, making the production process simple and suitable for industrial applications.

Study on Formation Mechanism of Fayalite (Fe2SiO4) by Solid State Reaction in Sintering Process

JOM ◽  
2017 ◽  
Vol 70 (4) ◽  
pp. 539-546 ◽  
Author(s):  
Zhongbing Wang ◽  
Bing Peng ◽  
Lifeng Zhang ◽  
Zongwen Zhao ◽  
Degang Liu ◽  
...  
Keyword(s):  
Solid State ◽  
Formation Mechanism ◽  
Solid State Reaction ◽  
Sintering Process

scholarly journals Metallurgical Mechanism and Optical Properties of CuSnZnSSe Powders Using a 2-Step Sintering Process

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Tai-Hsiang Liu ◽  
Fei-Yi Hung ◽  
Truan-Sheng Lui ◽  
Kuan-Jen Chen
Keyword(s):  
Optical Properties ◽  
Solid State ◽  
Solid State Reaction ◽  
Raman Shift ◽  
Sintering Process ◽  
Composition And Structure ◽  
Absorber Material ◽  
The Stability ◽  
Stability Of Structure ◽  
Sintering Processes

Cu2SnZn(S + Se)4is an excellent absorber material for solar cells. This study obtained Cu2SnZn(S + Se)4powders through solid state reaction by the ball milling and sintering processes from elemental Cu, Zn, Sn, S, and Se without using either polluting chemicals or expensive vacuum facilities. Ratios of S/S + Se in CuSnZnSSe were controlled from 0 to 1. The results showed that the 2-step sintering process (400°C for 12 hrs and then 700°C for 1 hr) was able to stabilize the composition and structure of the CuSnZnSSe powders. The crystallized intensity of the CuSnZnS matrix decreased with increasing the Se content. Raising the Se content restrained the SnS phase and reduced the resistance of the absorber layer. In addition, Raman data confirmed that Se caused a Raman shift in the CuSnZnSSe matrix and enhanced the optical properties of the CuSnZnSSe powders. For the interface of CuSnZnSSe film and Mo substrate, Mo could diffuse into CuSnZnSSe matrix after 200°C annealing. The interface thermal diffusion of CuSnZnSSe/ZnS improved the effects of stack to enhance the stability of structure.

scholarly journals Influence of Carbon Content on Superconductivity of Bi2Sr2CaCu2Ox

2017 ◽  
Vol 5 (1) ◽  
pp. 77
Author(s):  
Deawha Soh ◽  
Zhanguo Fan ◽  
N. Korobova
Keyword(s):  
Solid State ◽  
Grain Boundary ◽  
Critical Current Density ◽  
Carbon Content ◽  
Critical Current ◽  
Conventional Method ◽  
Current Density ◽  
Solid State Reaction ◽  
Sintering Process ◽  
Shs Method

<p>Bi<sub>2</sub>Sr<sub>2</sub>CaCu<sub>2</sub>O<sub>X</sub> was prepared by the conventional method of solid state reaction and SHS method. The samples were annealed in different atmosphere in order to examine the influence of atmospheres on the carbon contents in the Bi<sub>2</sub>Sr<sub>2</sub>CaCu<sub>2</sub>O<sub>X</sub> compound. The lowest carbon content in Bi<sub>2</sub>Sr<sub>2</sub>CaCu<sub>2</sub>O<sub>X</sub> could be attended when the sample was annealed in O<sub>2</sub> at 800 °C for 100 hours. The CO<sub>2</sub> in air pollute the samples and increase the carbon content in the sintering process. The critical current density of the Bi<sub>2</sub>Sr<sub>2</sub>CaCu<sub>2</sub>O<sub>X</sub> samples will decrease with the increasing carbon contents in the samples. The impurity carbon will deposit in the grain boundary, which makes critical current density lower.</p>

Dielectric Properties of Mg-Doped CaCu3Ti4O12 Measured at High Frequencies

2014 ◽  
Vol 895 ◽  
pp. 190-193
Author(s):  
Mohd Fariz Ab Rahman ◽  
Sabar Derita Hutagalung ◽  
Julie Juliewatty Mohamed ◽  
Mohd Fadzil Ain
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Solid State ◽  
Dielectric Loss ◽  
Solid State Reaction ◽  
Single Phase ◽  
Raw Materials ◽  
Sintering Process ◽  
High Frequencies ◽  
Mg Doped

Mg-doped CaCu3Ti4O12 (CCTO) systems were prepared by solid state reaction using raw materials of CaCO3, CuO, TiO2 and MgO. The samples were calcined at 900°C for 12 hours and sintered at 1030°C for 10 hours. Single phase CCTO formed after sintering process. It was found that dielectric constant and dielectric loss of CCTO improved by MgO dopant.

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