Differentiated Electric Behaviors of La_2/3Cu₃Ti₄O₁₂ Ceramics Prepared by Different Methods

Abstract

Microstructure and electric behaviors of La 2/3 Cu 3 Ti 4 O 12 (LCTO) ceramics prepared by the sol-gel method (SG) and solid-state method (SS) have been systemically investigated. The results indicated that LCTO-SG ceramics sintered at 1105°C for 15 h showed larger grain size, higher density, and especially higher dielectric constant up to about 0.9-1.6 3 10 4 at 10 2~1 0 5 Hz compared to LCTO-SS ceramics. The higher dielectric constant of the LCTO-SG ceramics might be due to the stronger internal barrier layer capacitor (IBLC) effect. More notably, compared with LCTO-SS ceramics, two kinds of dielectric anomalies, one conduction activation energy value and same activation energies for the conduction and relaxation process in LCTO-SS ceramics, the LCTO-SG ceramics showed three kinds of dielectric anomalies, two values of conduction activation energy, and decrease in conduction activation energy with increasing temperature. The activation energies for the conduction and relaxation process in LCTO-SG ceramics showed great difference below about 210°C, suggesting that the mechanism of electrical conduction and dielectric relaxation seem to be different in LCTO-SG ceramics. These remarkable differences in electric behaviors of LCTO ceramics prepared by sol-gel and solid-state methods were firstly found and analyzed.

Sintering Temperature, Frequency, and Temperature Dependent Dielectric Properties of Na0.5Sm0.5Cu3Ti4O12 Ceramics

“…The ceramics CS-1075 and CS-1100 showed the highest ε′ (>10 3 ) over the entire temperature range. It is known that temperature stability of permittivity is an important quality factor and can be evaluated by the thermal coefficient of permittivity (TCK) [21,22] % 100…”

Phase Formation and Enhanced Dielectric Response of Y2/3Cu3Ti4O12 Ceramics Derived from the Sol–Gel Process

“…reported that NBCTO ceramics exhibited giant permittivity . In addition, the fabrication methods have significant effects on the dielectric relaxation behaviors, the electrical conductivity of grain boundaries (GBs), and the activation energy levels at the GBs and bulk . However, to the best of our knowledge, the phase formation mechanism of YCTO precursors and the YCTO ceramics prepared by the sol–gel method have not yet been reported.…”

“…16 In addition, the fabrication methods have significant effects on the dielectric relaxation behaviors, the electrical conductivity of grain boundaries (GBs), and the activation energy levels at the GBs and bulk. 9,10,17 However, to the best of our knowledge, the phase formation mechanism of YCTO precursors and the YCTO ceramics prepared by the sol-gel method have not yet been reported. Therefore, it is still worthwhile to prepare the YCTO ceramics by the sol-gel method and investigate the electrical properties and dielectric mechanism in more details.…”

High Dielectric Constant and Dielectric Relaxations in La2/3Cu3Ti4O12 Ceramics

“…[9,[13][14][15][16][17][18][19][20][21] have been found to have the similar high dielectric constant as CaCu 3 Ti 4 O 12 , which revises the report by Subramanian [2] and brings new questions about the physical origin of dielectric response in ACu 3 Ti 4 O 12 ceramics. Internal barrier layer capacitor (IBLC) effects related to defect structure in grain and grain boundaries have been widely adopted to explain the origin of high dielectric response in these ACu 3 Ti 4 O 12 ceramics [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28].…”