HIGH DIELECTRIC PROPERTIES OF LOW-TEMPERATURE SINTERED (Ca0.5Cu0.5)TiO3 CERAMICS

2011 ◽  
Vol 01 (02) ◽  
pp. 203-207 ◽  
Author(s):  
JIAN-CONG YUAN ◽  
YUAN-HUA LIN ◽  
BO CHENG ◽  
CE-WEN NAN
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Impedance Spectrum ◽  
Dielectric Constants ◽  
Sintering Process ◽  
Remarkable Effect ◽  
High Dielectric Permittivity ◽  
Wide Range ◽  
High Dielectric

High dielectric-permittivity ( Ca0.5Cu0.5)TiO3 -based ceramics have been prepared by a sol-gel method combined with a solid state sintering process. The results indicate that the additives of H3BO3 have a remarkable effect on the sintering temperature, microstructure and dielectric properties. High density ( Ca0.5Cu0.5)TiO3 bulk ceramics can be obtained after sintering at 900°C. The as-sintered ceramics show high dielectric constants (~1000), and low losses (~0.05). The dielectric properties are nearly independent of frequency and temperature in a wide range. The activation energy is calculated as about 0.50 eV by impedance spectrum method.

Microstructure and Dielectric Properties of LixTixNi1-2xO Thin Films

2008 ◽  
Vol 368-372 ◽  
pp. 1817-1819
Author(s):  
Cui Hua Zhao ◽  
Bo Ping Zhang ◽  
Yong Liu ◽  
Song Jie Li
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Spin Coating ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Co Doping ◽  
Grain Sizes ◽  
Uniform Microstructure ◽  
Coating Method ◽  
High Dielectric

LixTixNi1-2xO (x =0, 10 and 20 at. %) thin films with 200 nm in thickness were deposited on Pt/Ti/SiO2/Si (100) by a sol-gel spin-coating method. All samples have a uniform microstructure. The grain sizes grew from 100 nm to 300 nm by co-doping Li and Ti. The LiTiNiO thin films consist of NiO, NiTiO3 and Li2NiO2, while the Li-free thin films consist of NiO, NiTiO3 and NiTi0.99O3. The dielectric properties of the LiTiNiO thin films improved obviously by co-doping Li and Ti, but excess Li increases the amount of Li2NiO2 phase and decreases the dielectric properties. The dielectric constants at 100 Hz for the Li0.1Ti0.1Ni0.8O and Li0.2Ti0.2Ni0.6O thin films are 506 and 388 respectively. Appropriate co-doping contents of Li and Ti are important to obtain a high dielectric property.

The Effects of Sintering Temperature on the Dielectric Properties of Sr(FeNb)0.5O3 Doped with Ba(Zr0.25Ti0.75)O3

2016 ◽  
Vol 675-676 ◽  
pp. 651-654
Author(s):  
Lalita Tawee ◽  
Kachaporn Sanjoom ◽  
Thanatep Phatungthane ◽  
Tawee Tunkasiri ◽  
Gobwute Rujijanagul ◽  
...  
Keyword(s):  
Grain Size ◽  
Dielectric Properties ◽  
Solid State ◽  
Wide Temperature Range ◽  
Solid State Reaction ◽  
Sintering Temperature ◽  
Dielectric Constants ◽  
Solid State Reaction Technique ◽  
Cubic Symmetry ◽  
High Dielectric

In this work, ceramics of Sr(Fe0.5Nb0.5O3) doped with Ba(Zr0.25Ti0.75)O3 (10 mol%), were synthesized by a solid-state reaction technique. The powders were calcined at 1300 °C for 12 hr and then sintered at 1400-1500 °C for 4 hr. Effects of sintering temperature on the properties of the ceramic were studied. Phase formation, microstructure, and dielectric properties were investigated. The ceramics exhibited a perovskite structure with cubic symmetry. Grain size of the ceramics increased with increasing the sintering temperature. The ceramics exhibited a dielectric relaxation like behavior with high dielectric constants over a wide temperature range

Microstructural and Dielectric Properties of Conventional and Microwave Sintered CaCu3Ti4O12 Ceramics

2012 ◽  
Vol 727-728 ◽  
pp. 1063-1068 ◽  
Author(s):  
Daniel Thomazini ◽  
Maria Virginia Gelfuso ◽  
Gabriel Moreira Lima ◽  
José Antônio Eiras
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Hold Time ◽  
Microwave Oven ◽  
Dielectric Constants ◽  
Chemical Route ◽  
Microelectronic Devices ◽  
Sintering Conditions ◽  
Strong Candidate ◽  
High Dielectric

ts well known that CaCu3Ti4O12(CCTO) ceramic presents high dielectric constants, which makes it a strong candidate to be used in microelectronic devices. Several routes were proposed to obtain CCTO crystalline phase, influencing in microstructure and sintering conditions of the ceramics. In this study CCTO powders were produced by a new chemical route, providing reduction on hold time and sintering temperature. Furthermore, the sintering was performed in conventional and microwave oven that produced different microstructures. In this way, the microstructure and dielectric properties of these ceramics were evaluated and compared, showing the higher values of dielectric constant due to lower grain size and reduced copper-rich phase on grain boundary presented by microwave sintered ceramics.

Electron microscopy studies of PZT ferroelectric film capacitor structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1364-1365
Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  
Keyword(s):  
Electric Fields ◽  
Sol Gel ◽  
Ferroelectric Material ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Lead Zirconium Titanate ◽  
Si Substrate ◽  
Film Capacitor ◽  
Pzt Films ◽  
High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

scholarly journals Microwave Sintering and Microwave Dielectric Properties of (1–x)Ca0.61La0.26TiO3-xNd(Mg0.5Ti0.5)O3 Ceramics

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 438
Author(s):  
Shuwei Yang ◽  
Bingliang Liang ◽  
Changhong Liu ◽  
Jin Liu ◽  
Caisheng Fang ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Mobile Communications ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Microwave Dielectric Properties ◽  
Conventional Heating ◽  
Sintering Process ◽  
Microwave Dielectric ◽  
Sintering Time ◽  
Frequency Temperature

The (1–x)Ca0.61La0.26TiO3-xNd(Mg0.5Ti0.5)O3 [(1–x)CLT-xNMT, x = 0.35~0.60] ceramics were prepared via microwave sintering. The effects of sintering temperature and composition on the phase formation, microstructure, and microwave dielectric properties were investigated. The results show that the microwave sintering process requires a lower sintering temperature and shorter sintering time of (1–x)CLT-xNMT ceramics than conventional heating methods. All of the (1–x)CLT-xNMT ceramics possess a single perovskite structure. With the increase of x, the dielectric constant (ε) shows a downward trend; the quality factor (Qf) drops first and then rises significantly; the resonance frequency temperature coefficient (τf) keeps decreasing. With excellent microwave dielectric properties (ε = 51.3, Qf = 13,852 GHz, τf = −1.9 × 10−6/°C), the 0.65CLT-0.35NMT ceramic can be applied to the field of mobile communications.

Microstructure and Microwave Dielectric Properties of BaTi4O9 Ceramics Derived from a Sol-Gel Precursor

2011 ◽  
Vol 326 ◽  
pp. 127-130
Author(s):  
Xian Li Huang ◽  
Fu Ping Wang ◽  
Ying Song
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Sol Gel ◽  
Microwave Dielectric Properties ◽  
Sintering Process ◽  
Temperature Coefficients ◽  
Microwave Dielectric ◽  
Ceramic Samples ◽  
Quality Factor Q

In the present work, the microstructure and microwave dielectric properties of BaTi4O9 ceramics derived from a sol-gel precursor were presented. Density measuring results demonstrated that the largest densities of ceramic sample about 96.7% could be reached by virtue of a cool iso-static press and a sintering process at at 1300 °C for 6 hours. The dielectric constant (εr), quality factor (Q×f) and the temperature coefficients (τf) of the BaTi4O9 ceramic samples were 36.65, 28000 GHz, +20.2 ppm/°C, respectively. XRD, SEM and XPS were used to characterize the microstructure of the ceramics samples. Substantial Ti3+ was proposed to be the cause of dielectric loss.

scholarly journals Dielectric and varistor properties of rare-earth-doped ZnO and CaCu3Ti4O12 composite ceramics

2013 ◽  
Vol 03 (01) ◽  
pp. 1350001 ◽  
Author(s):  
Huafei Lu ◽  
Yuanhua Lin ◽  
Jiancong Yuan ◽  
Cewen Nan ◽  
Kexin Chen
Keyword(s):  
Rare Earth ◽  
Sol Gel ◽  
Nonlinear Coefficient ◽  
Composite Ceramic ◽  
Dielectric Behavior ◽  
Composite Ceramics ◽  
High Dielectric Permittivity ◽  
Doped Zno ◽  
Co Precipitation ◽  
High Dielectric

To investigate the multi-functional ceramics with both high permittivity and large nonlinear coefficient, we have prepared rare-earth Tb -and- Co doped ZnO and TiO 2-rich CaCu3Ti4O12 (TCCTO) powders by chemical co-precipitation and sol–gel methods respectively, and then obtained the TCCTO/ ZnO composite ceramics, sintered at 1100°C for 3 h in air. Analyzing the composite ceramics of the microstructure and phase composition indicated that the composite ceramics were composed of the main phases of ZnO and CaCu3Ti4O12 (CCTO). Our results revealed that the TCCTO/ ZnO composite ceramics showed both high dielectric and good nonlinear electrical behaviors. The composite ceramic of TCCTO: ZnO = 0.3 exhibited a high dielectric constant of ~210(1 kHz) with a nonlinear coefficient of ~11. The dielectric behavior of TCCTO/ ZnO composite could be explained by the mixture rule. With the high dielectric permittivity and tunable varistor behaviors, the composite ceramics has a potential application for the higher voltage transportation devices.

New Perovskite Nanomaterials and Their Integrations into High-k Dielectrics

2011 ◽  
Vol 2011 (CICMT) ◽  
pp. 000072-000077
Author(s):  
Minoru Osada ◽  
Takayoshi Sasaki
Keyword(s):  
Dielectric Properties ◽  
Room Temperature ◽  
Bottom Electrode ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Layered Perovskite ◽  
Layer By Layer ◽  
High K ◽  
High K Dielectric ◽  
High Dielectric

We report on a bottom-up manufacturing for high-k dielectric films using a novel nanomaterial, namely, a perovskite nanosheet (LaNb2O7) derived from a layered perovskite by exfoliation. Solution-based layer-by-layer assembly of perovskite nanosheets is effective for room-temperature fabrication of high-k nanocapacitors, which are directly assembled on a SrRuO3 bottom electrode with an atomically sharp interface. These nanocapacitors exhibit high dielectric constants (k &gt; 50) for thickness down to 5 nm while eliminating problems resulting from the size effect. We also investigate dielectric properties of perovskite nanosheets with different compositions (LaNb2O7, La0.95Eu0.05Nb2O7, and Eu0.56Ta2O7) in order to study the influence of A- and B-site modifications on dielectric properties.

Effect of Process on the Dielectric Properties of BaTiO3-Based X9R Ceramics

2014 ◽  
Vol 906 ◽  
pp. 18-24 ◽  
Author(s):  
Bao Lin Zhang ◽  
Bin Bin Zhang ◽  
Ning Ning Wang ◽  
Jing Ming Fei
Keyword(s):  
Particle Size ◽  
Dielectric Properties ◽  
Milling Time ◽  
Sintering Temperature ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Sintered Ceramic ◽  
X Ray ◽  
Particle Size Analyzer

The effect of milling time and sintering process on the dielectric properties of BaTiO3-based X9R ceramics was investigated. The characterization of the raw powders and the sintered ceramic was carried out by X-ray diffraction and scanning electron microscopy. The particle size distribution of the mixed powders was examined by Laser Particle Size Analyzer. The results shown that with the milling time extended, the Cruie Peak was depressed, or even disappeared. Moreover, with the rise of sintering temperature, the dielectric constant of the ceramics increased and the dielectric loss decreased gradually. Eventually, by milling for 11h and sintering at 1090°Cfor 2h, good dielectric properties were obtained, which were ε25°C≥ 2526, εr/εr25°C≤± 12% (–55~200°C), tanδ≤1.12% (25°C).

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