Dielectric properties and defect chemistry of La and Tb co-doped BaTiO3 ceramics

2016 ◽  
Vol 681 ◽  
pp. 128-138 ◽  
Author(s):  
Da-Yong Lu ◽  
Yan-Yan Peng ◽  
Xin-Yu Yu ◽  
Xiu-Yun Sun
Keyword(s):  
Dielectric Properties ◽  
Defect Chemistry ◽  
Co Doped

scholarly journals The Primary Origin of Excellent Dielectric Properties of (Co, Nb) Co-Doped TiO2 Ceramics: Electron-Pinned Defect Dipoles vs. Internal Barrier Layer Capacitor Effect

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3230
Author(s):  
Theeranuch Nachaithong ◽  
Narong Chanlek ◽  
Pairot Moontragoon ◽  
Prasit Thongbai
Keyword(s):  
Dielectric Properties ◽  
Loss Tangent ◽  
Barrier Layer ◽  
Dielectric Response ◽  
High Resistivity ◽  
Low Loss ◽  
Rutile Tio2 ◽  
Complex Defect ◽  
Very High ◽  
Co Doped

(Co, Nb) co-doped rutile TiO2 (CoNTO) nanoparticles with low dopant concentrations were prepared using a wet chemistry method. A pure rutile TiO2 phase with a dense microstructure and homogeneous dispersion of the dopants was obtained. By co-doping rutile TiO2 with 0.5 at.% (Co, Nb), a very high dielectric permittivity of ε′ » 36,105 and a low loss tangent of tanδ » 0.04 were achieved. The sample–electrode contact and resistive outer-surface layer (surface barrier layer capacitor) have a significant impact on the dielectric response in the CoNTO ceramics. The density functional theory calculation shows that the 2Co atoms are located near the oxygen vacancy, creating a triangle-shaped 2CoVoTi complex defect. On the other hand, the substitution of TiO2 with Nb atoms can form a diamond-shaped 2Nb2Ti complex defect. These two types of complex defects are far away from each other. Therefore, the electron-pinned defect dipoles cannot be considered the primary origins of the dielectric response in the CoNTO ceramics. Impedance spectroscopy shows that the CoNTO ceramics are electrically heterogeneous, comprised of insulating and semiconducting regions. Thus, the dielectric properties of the CoNTO ceramics are attributed to the interfacial polarization at the internal insulating layers with very high resistivity, giving rise to a low loss tangent.

Ferroelectric relaxor behavior and dielectric properties of La/Y co-doped (Ba0.9Ca0.1)(Zr0.2Ti0.8)O3 ceramics

2016 ◽  
Vol 27 (6) ◽  
pp. 6150-6155 ◽  
Author(s):  
Anqi Li ◽  
Yu Wang ◽  
Liu Yang ◽  
Ping Yang ◽  
Gang Wang ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Relaxor Behavior ◽  
Ferroelectric Relaxor ◽  
Co Doped

scholarly journals Structure, Defects and Microwave Dielectric Properties of Al-doped and Al/Nd Co-doped Ba4Nd9.33Ti18O54 Ceramics

2021 ◽  
Author(s):  
Weijia Guo ◽  
Zhiyu Ma ◽  
Yu Luo ◽  
Yugu Chen ◽  
Zhenxing Yue ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Resonant Frequency ◽  
Microwave Dielectric Properties ◽  
Relative Dielectric Constant ◽  
Doping Amount ◽  
Solid State Method ◽  
Depolarization Current ◽  
Structure Defects ◽  
Microwave Dielectric ◽  
Co Doped

Abstract Ba4Nd9.33Ti18-zAl4z/3O54 (BNT-A, 0 ≤ z ≤ 2) and Ba4Nd9.33+z/3Ti18-zAlzO54 (BNT-AN, 0 ≤ z ≤ 2) ceramics were prepared by solid state method, and the effects of the two doping methods on microwave dielectric properties were compared. As the doping amount z increased, the relative dielectric constant (εr) and the temperature coefficient of resonant frequency (τf) values of the ceramics decreased, and the quality factor (Q, usually expressed by Q×f, where f is the resonant frequency) of the ceramics obviously increased when z ≤ 1.5. With the same z value, the εr and Q×f values of Al/Nd co-doped ceramics are both higher than those of Al-doped ceramics. Rietveld refinement, Raman spectroscopy and thermally stimulated depolarization current (TSDC) technique were applied to clarify the relationship among the structure, defects and microwave dielectric properties. It is shown that the Q×f values of those ceramics were closely related to the strength of the A-site cation vibration and the concentration of oxygen vacancies (B). Excellent microwave dielectric properties of εr = 72.2, Q×f = 16480 GHz, and τf = +14.3 ppm/℃ were achieved in BNT-AN ceramics with z = 1.25.

Investigation on structural, optical and dielectric properties of Co doped ZnO nanoparticles synthesized by gel-combustion route

2012 ◽  
Vol 177 (5) ◽  
pp. 428-435 ◽  
Author(s):  
Sajid Ali Ansari ◽  
Ambreen Nisar ◽  
Bushara Fatma ◽  
Wasi Khan ◽  
A.H. Naqvi
Keyword(s):  
Dielectric Properties ◽  
Zno Nanoparticles ◽  
Gel Combustion ◽  
Combustion Route ◽  
Doped Zno ◽  
Co Doped

Electrical and Dielectric Properties of Aluminum/Niobium Co-doped CaCu3Ti4O12Ceramics

2016 ◽  
Vol 492 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Ali Wen ◽  
Daqing Yuan ◽  
Xiaohong Zhu ◽  
Jianguo Zhu ◽  
Dingquan Xiao ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Electrical And Dielectric Properties ◽  
Co Doped
Sign in / Sign up

Export Citation Format

Share Document