B. Shri Prakash

Ferroelectriclike and pyroelectric behavior of CaCu3Ti4O12 ceramics

A ferroelectriclike hysteresis loop was obtained at room temperature for CaCu3Ti4O12 (CCTO) ceramic. The remnant polarization and coercive field for 1100 °C/5 h sintered CaCu3Ti4O12 ceramics were 0.063 μC/cm2 and 195 V/cm, respectively. Remnant polarization increased while the coercive field decreased with increase in sintering temperature/duration, implying that these were microstructural dependent. The observation of the hysteresis loop for CCTO ceramic was corroborated by its pyroelectric behavior, and the pyroelectric current at room temperature was −0.0028 nA. These findings were attributed to the presence of mixed-valent Ti ions, apart from off center displacement of Ti ions in TiO6 octahedra.

Extreme values of relative permittivity and dielectric relaxation in Sr2SbMnO6 ceramics

A polycrystalline ceramic of

Effect of composition on the polarization and ohmic resistances of LSM/YSZ composite cathodes in solid oxide fuel cell

Sr_2SbMnO_6

Dielectric behavior of CCTO/epoxy and Al-CCTO/epoxy composites

(SSM) was fabricated using the powders obtained by the conventional solid-state reaction route. The dielectric measurements of the ceramic were carried out as a function of frequency (100 Hz–10 MHz) and temperature (190-360 K). SSM exhibited higher relative permittivity

Effect of sintering conditions on the dielectric properties of CaCu3Ti4O12 and La2/3Cu3Ti4O12 ceramics: A comparative study

(\sim2 \times 10^5

Influence of sintering conditions and doping on the dielectric relaxation originating from the surface layer effects in CaCu3Ti4O12 ceramics

for 1 kHz at 360 K) than that for the recently known high permittivity ceramic

Microstructural and dielectric properties of donor doped (La3+) CaCu3Ti4O12 ceramics

CaCu_3Ti_4O_{12}

The influence of the segregation of Cu-rich phase on the microstructural and impedance characteristics of CaCu3Ti4O12 ceramics

(CCTO). It decreased to a relatively low value (

Effect of sintering conditions on the microstructural, dielectric, ferroelectric and varistor properties of CaCu3Ti4O12 and La2/3Cu3Ti4O12 ceramics belonging to the high and low dielectric constant members of ACu3M4O12 (A=alkali, alkaline-earth metal, rare-earth metal or vacancy, M=transition metal) family of oxides

\sim2 \times 10^3

Effect of the addition of B2O3 and BaO-B2O3-SiO2 glasses on the microstructure and dielectric properties of giant dielectric constant material CaCu3Ti4O12

for 1 kHz) on decreasing the temperature down to 195 K. The modified Cole–Cole equation that included the conductivity term was used to describe the dielectric spectra of the ceramic. Impedance spectroscopy was employed to determine the electrical parameters (resistance, capacitance and relaxation time) of the grain and the grain boundary. The grain and grain boundary conduction and the dielectric relaxation time followed an Arrhenius law associated with activation energies of 0.22 eV, 0.35 eV and 0.24 eV, respectively. Nearly equal activation energies for dielectric relaxation and grain conduction revealed a possibility of invoking a common mechanism to rationalize the permittivity data. The capacitance and resistance associated with the grain boundary were found to be higher than that associated with the grain to a great extent. The incidence of giant relative permittivity and the other experimental findings support the Maxwell–Wagner type of mechanism.