Influence of atmospheres on the dielectric properties of calcium copper titanate ceramics

2019 ◽  
Vol 102 (9) ◽  
pp. 5271-5283
Author(s):  
Disna P. Samarakoon ◽  
Nirmal Govindaraju ◽  
Raj N. Singh
Keyword(s):  
Dielectric Properties ◽  
Calcium Copper Titanate ◽  
Titanate Ceramics

Dielectric Properties of Sol-Gel Prepared Ni-Doped CaCu3Ti4O12 Ceramics

2012 ◽  
Vol 204-208 ◽  
pp. 4193-4196
Author(s):  
Lei Jiao ◽  
Hui Li ◽  
Yan Wei Yang ◽  
Tian Ping Wang
Keyword(s):  
Dielectric Properties ◽  
Dielectric Loss ◽  
Sol Gel ◽  
Low Frequency ◽  
Frequency Region ◽  
Dielectric Constants ◽  
High Frequency Region ◽  
Xrd Pattern ◽  
Calcium Copper Titanate ◽  
Titanate Ceramics

Dielectric properties of sol–gel prepared Ni-doped calcium copper titanate Ceramics (CCNTO) are investigated. For the x of CaCu3NixTi4O12+x is 0, 0.1, 0.2, 0.3 respectively. The XRD pattern shows that crystal structure of the sample without Ni is basically single-phase. The dielectric properties of CCNTO were analyzed by Agilent 4294A. The experimental results show that the sample has a better dielectric properties when x=0.2. The maximum dielectric constants is found when x=0.2. The dielectric loss decreased with the increases of Ni in the low frequency region, the high frequency region is just the opposite, the sample has lower dielectric loss in the low frequency region when x=0.2.

Influence of Alumina Dopant and Environment on the Electrical Properties of Calcium Copper Titanate Ceramics

2021 ◽  
Vol 21 (4) ◽  
pp. 2148-2162
Author(s):  
Disna P. Samarakoon ◽  
Raj N. Singh
Keyword(s):  
Dielectric Properties ◽  
Nitrogen Atmosphere ◽  
Charge Accumulation ◽  
Low Frequencies ◽  
Testing Environment ◽  
Calcium Copper Titanate ◽  
Large Dielectric Constant ◽  
Electrical And Dielectric Properties ◽  
The Stability ◽  
Titanate Ceramics

Calcium copper titanate (CaCu3Ti4O12; CCTO) ceramics are useful as capacitor dielectrics for many applications. In this study the effect of doping with alumina and testing atmospheres in air and dry N2 on the stability and reproducibility of electrical and dielectric properties of CCTO-xAl2O3 system, where x = 0, 0.5, and 4 wt.% as a function of temperature are investigated. Solid-state synthesis route is used to fabricate the pure and doped CCTO samples sintered at 1080 °C and 1100 °C for 5 h in air. Stable and reproducible dielectric properties are obtained only by switching the measuring atmosphere from air to dry N2. Increased space charge accumulation at the grain boundaries leading to large dielectric constant (ε′) and tan δ are measured in air. Much lower tan δ values of 0.021–0.020 are obtained with a large ε′ (8,815–11,090) at low frequencies (500–800 Hz) in N2 at 23 °C for 0.5 wt.% alumina in both samples sintered at 1080 °C and 1100 °C. These results clearly demonstrate that testing environment can dominate the dielectric properties of pure and alumina-doped CCTO at low frequencies unless measured in dry nitrogen atmosphere to achieve intrinsic behavior useful for applications as capacitors.

Microwave Dielectric Properties of Lanthanide Titanate Ceramics

1993 ◽  
Vol 32 (Part 1, No. 9B) ◽  
pp. 4327-4331 ◽  
Author(s):  
Junichi Takahashi ◽  
Keisuke Kageyama ◽  
Kouhei Kodaira
Keyword(s):  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric ◽  
Titanate Ceramics

Preparation of barium titanate ceramics from amorphous fine particles of the Ba–Ti–O system and its dielectric properties

1995 ◽  
Vol 10 (2) ◽  
pp. 306-311 ◽  
Author(s):  
S. Wada ◽  
T. Suzuki ◽  
T. Noma
Keyword(s):  
Dielectric Properties ◽  
Barium Titanate ◽  
Curie Temperature ◽  
Decomposition Method ◽  
Fine Particles ◽  
Nitrate Solution ◽  
Pressing Method ◽  
Calcination Temperatures ◽  
Grain Sizes ◽  
Titanate Ceramics

Using titanium nitrate solution stabilized by chelation, amorphous fine particles of the Ba-Ti-O system were prepared by the mist decomposition method in air. After calcination of these particles, barium titanate ceramics were prepared using the hot uniaxial pressing method, and various properties were investigated. As a result, the grain sizes could be controlled over the range from 58 nm to 187 nm by the sintering temperatures and/or the calcination temperatures, keeping the density almost constant. Moreover, the dielectric properties of the samples showed that the relative permittivity decreased with decreasing grain size, and Curie temperature also shifted to lower temperatures in the same way. In this study, we first found that Curie temperature existed in the barium titanate ceramics with grain sizes from 58 to 147 nm.

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