scholarly journals Exploring the Interrelation between Urbach Energy and Dielectric Constant in Hf-Substituted BaTiO3

ACS Omega ◽  
2021 ◽  
Author(s):  
Omkar V. Rambadey ◽  
Anil Kumar ◽  
Aanchal Sati ◽  
Pankaj R. Sagdeo
2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Wasan Al-Taa’y ◽  
Mohammed Abdul Nabi ◽  
Rahimi M. Yusop ◽  
Emad Yousif ◽  
Bashar Mudhaffar Abdullah ◽  
...  

Optical properties of pure and doped poly(vinyl chloride) (PVC) films, prepared by using casting technique, with different nanosize zinc oxide (ZnO) concentrations (1–20) wt% have been studied. Parameters such as extinction coefficient, refractive index, real and imaginary parts, Urbach energy, optical conductivity, infinitely high frequency dielectric constant, and average refractive index were studied by using the absorbance and transmittance measurement from computerized UV-visible spectrophotometer (Shimadzu UV-1601 PC) in the spectral range 200–800 nm. This study reveals that the optical properties of PVC are affected by the doping of ZnO where the absorption increases and transmission decreases as ZnO concentration increases. The extinction coefficient, refractive index, real and imaginary parts, infinitely high frequency dielectric constant, and average refractive index values were found to increase with increasing impurity percentage. The Urbach energy values are found to be decreasing with increasing ZnO concentration. The optical conductivity increased with photon energy after being doped and with the increase of ZnO concentration.


Author(s):  
E. L. Hall ◽  
A. Mogro-Campero ◽  
N. Lewis ◽  
L. G. Turner

There have been a large number of recent studies of the growth of Y-Ba-Cu-O thin films, and these studies have employed a variety of substrates and growth techniques. To date, the highest values of Tc and Jc have been found for films grown by sputtering or coevaporation on single-crystal SrTiO3 substrates, which produces a uniaxially-aligned film with the YBa2Cu3Ox c-axis normal to the film plane. Multilayer growth of films on the same substrate produces a triaxially-aligned film (regions of the film have their c-axis parallel to each of the three substrate <100> directions) with lower values of Jc. Growth of films on a variety of other polycrystalline or amorphous substrates produces randomly-oriented polycrystalline films with low Jc. Although single-crystal SrTiO3 thus produces the best results, this substrate material has a number of undesireable characteristics relative to electronic applications, including very high dielectric constant and a high loss tangent at microwave frequencies. Recently, Simon et al. have shown that LaAlO3 could be used as a substrate for YBaCuO film growth. This substrate is essentially a cubic perovskite with a lattice parameter of 0.3792nm (it has a slight rhombohedral distortion at room temperature) and this material exhibits much lower dielectric constant and microwave loss tangents than SrTiO3. It is also interesting from a film growth standpoint since it has a slightly smaller lattice parameter than YBa2Cu3Ox (a=0.382nm, b=c/3=0.389nm), while SrTiO3 is slightly larger (a=0.3905nm).


2020 ◽  
Vol 8 (32) ◽  
pp. 16661-16668
Author(s):  
Huayao Tu ◽  
Shouzhi Wang ◽  
Hehe Jiang ◽  
Zhenyan Liang ◽  
Dong Shi ◽  
...  

The carbon fiber/metal oxide/metal oxynitride layer sandwich structure is constructed in the electrode to form a mini-plate capacitor. High dielectric constant metal oxides act as dielectric to increase their capacitance.


Author(s):  
Peng Wang ◽  
Zhongbin Pan ◽  
Weilin Wang ◽  
Jianxu Hu ◽  
Jinjun Liu ◽  
...  

High-performance electrostatic capacitors are in urgent demand owing to the rapidly development of advanced power electronic applications. However, polymer-based composite films with both high breakdown strength (Eb) and dielectric constant...


1980 ◽  
Vol 130 (1) ◽  
pp. 65 ◽  
Author(s):  
V.D. Gorobchenko ◽  
Evgenii G. Maksimov

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