Relations between the Morphology of ZnO Powders and the Electrical Performance of ZnO Varistors

2007 ◽  
Vol 336-338 ◽  
pp. 672-675
Author(s):  
Witold Mielcarek ◽  
Slavko Bernik ◽  
Krystyna Prociów
Keyword(s):  
Metal Oxide ◽  
Electronic Devices ◽  
Electrical Performance ◽  
Ohmic Behavior ◽  
Wide Range ◽  
Zno Powders ◽  
Zno Varistors ◽  
Sintering Conditions ◽  
Working Parameters ◽  
Zno Ceramics

Because of their unusual properties – non-ohmic behavior and the ability to absorb a lot of energy – metal-oxide varistors are widely used for the protection of electrical and electronic devices against over-voltages. ZnO ceramics have varistor properties because of their metal-oxide additives and the microstructures developed during sintering. The value of the varistor voltage depends largely on the number of conducting ZnO grains between the electrodes; this can be set by controlling the thickness of the device or the size of the grains. The desired grain size can be achieved by altering the composition of the metal-oxide additives and the sintering conditions. In this work the grain growth was controlled by combining two ZnO powders of differing sinterability in the starting material. Also, the use of BaBiO2.77 as a precursor for Bi2O3 is an innovation in varistor technology that makes it possible to reduce the amount of added metal oxides. As a result, a variety of varistors with good varistor properties and a wide range of working parameters were produced.

Electrical Properties of ZnO-Bi2O3 Metal Oxide Heterojunction — A Clue of a Role of Intergranular Layers in ZnO Varistors

1981 ◽  
Vol 5 ◽  
Author(s):  
Kazuo Eda
Keyword(s):  
Thin Film ◽  
Electrical Properties ◽  
Metal Oxide ◽  
Oxide Thin Film ◽  
Thin Film Thickness ◽  
Metal Oxide Thin Film ◽  
Zno Varistors ◽  
Current Characteristics ◽  
Zno Ceramics

ABSTRACTZinc Oxide (ZnO) Ceramics-Bismuth Oxide (Bi2O3) Metal Oxide thin film heterojunction made by sputtering technique showed a highly non-Ohmic property. The voltage-current characteristics and the dielectric properties showed dependence on Bi2O3 metal oxide thin film thickness.In this paper after reviewing and discussing the electrical properties of ZnO varistors, the role of intergranular layers in the ZnO varistor is discussed based on experimental results with the heterojunction.

Effectively enhanced comprehensive electrical performance of ZnO varistors by a fast combinatorial refinement method

2021 ◽  
Vol 133 ◽  
pp. 105945
Author(s):  
Zhuyun Li ◽  
Xin Ren ◽  
Xin Wang ◽  
Wanli You ◽  
Meilian Zhong ◽  
...  
Keyword(s):  
Electrical Performance ◽  
Refinement Method ◽  
Zno Varistors

Strain-engineering in AlGaN/GaN HEMTs: impact of silicon nitride passivation layer on electrical performance

2021 ◽  
Author(s):  
Sanghamitra Das ◽  
Taraprasanna Dash ◽  
Devika Jena ◽  
Eleena Mohapatra ◽  
C K Maiti
Keyword(s):  
Experimental Data ◽  
Compressive Strain ◽  
Cutoff Frequency ◽  
Strain Engineering ◽  
Electrical Performance ◽  
Current Gain ◽  
Great Promise ◽  
High Electron ◽  
Wide Range ◽  
Gan Hemts

Abstract In this work, we present a physics-based analysis of two-dimensional electron gas (2DEG) sheet carrier density and other microwave characteristics such as transconductance and cutoff frequency of AlxGa1-xN/GaN high electron mobility transistors (HEMT). An accurate polarization-dependent charge control-based analysis is performed for microwave performance assessment in terms of current, transconductance, gate capacitances, and cutoff frequency of lattice-mismatched AlGaN/GaN HEMTs. The influence of stress on spontaneous and piezoelectric polarization is included in the simulation of an AlGaN/GaN HEMT. We have shown the change in threshold voltage (Vt) due to tensile and compressive strain with different gate lengths. Also, the influence of stress due to the change in nitride thickness is presented. Our simulation results for drain current, transconductance, and current-gain cutoff frequency for various gate length devices are calibrated and verified with experimental data over a wide range of gate and drain applied voltages, which are expected to be useful for microwave circuit design. The predicted transconductance, drain conductance, and operation frequency are quite close to the experimental data. The AlGaN/GaN heterostructure HEMTs with nitride passivation layers show great promise as a candidate in future high speed and high power applications.

scholarly journals Wide range frequency tuning in vacuum electronic devices

2003 ◽  
Author(s):  
V.G. Baryshevsky ◽  
K.G. Batrakov ◽  
N.A. Belous ◽  
A.A. Gurinovich ◽  
A.S. Lobko ◽  
...  
Keyword(s):  
Frequency Tuning ◽  
Electronic Devices ◽  
Wide Range ◽  
Vacuum Electronic Devices

scholarly journals A Comparative Study between the Effects of Magnetic and Nonmagnetic Dopants on the Properties of ZnO Varistors

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
A. Sedky ◽  
E. El-Suheel
Keyword(s):  
Comparative Study ◽  
Nonlinear Coefficient ◽  
Xrd Analysis ◽  
Breakdown Field ◽  
Doping Content ◽  
Leakage Currents ◽  
Electrical Conductivities ◽  
Zno Varistors ◽  
The Difference ◽  
Zno Ceramics

A comparative study between effects of Mn and Al on the properties of ZnO varistor sintered at 1200 is investigated by XRD, SEM hardness, and I-V measurements. Although both Mn and Al do not influence the well-known peaks related to wurtzite structure of ZnO ceramics, some other unknown peaks could be formed at higher doping content (). Also, the shape and size of grains are clearly different for both dopants. Average crystalline diameters, deduced from XRD analysis, are between 42 nm and 62 nm, which are 50 times lower than those obtained from SEM micrographs, while the oxygen vacancies deduced from EDAX analysis, are gradually decreased by doping content for both dopants. Interestingly, the values of breakdown field, nonlinear coefficient and barrier height are found to be higher in Mn samples as compared to Al samples, while the opposite is reported for leakage currents, hardness, and electrical conductivities. The values of are changed from 2.67 V/cm to 41.67 V/cm for Al, and from 1928 V/cm to 6571 V/cm for Mn. The conductivity of Al samples is higher than that of ZnO, and it is nearly (103–105) times the conductivity of Mn samples. These results are discussed in terms of the difference of magnetic moment and valence state between these two additives.

The role of imaging tests in electrotherapy

2020 ◽  
Vol 1 (54) ◽  
pp. 23-29
Author(s):  
Łukasz Mazurek ◽  
Agnieszka Kotalczyk ◽  
Michał Mazurek ◽  
Ewa Jędrzejczyk-Patej
Keyword(s):  
Sensitivity And Specificity ◽  
Therapeutic Process ◽  
Electronic Devices ◽  
Diagnosis And Treatment ◽  
Imaging Methods ◽  
Cardiac Implantable Electronic Devices ◽  
Wide Range

We currently have a wide range of different imaging tests that are constantly improving and developing. Each test has its sensitivity and specificity and is used in various fields of medicine. Knowledge of the possibilities of using imaging tests in electrotherapy is an important element of the diagnostic and therapeutic process. This article presents selected issues regarding the use of imaging methods in the diagnosis and treatment of patients with cardiac implantable electronic devices.

PSK Transciever designing using SystemVue

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Deepali Chaurasia
Keyword(s):  
Signal Processing ◽  
System Integration ◽  
Communication Systems ◽  
Energy Savings ◽  
Electronic Devices ◽  
Physical Space ◽  
Electronic System ◽  
System Level ◽  
Complex Nature ◽  
Wide Range

Since, the industrial electronics is trending towards more compact components and system integration, innovative products offering greater flexibility, quality, safety, reliability, energy savings, wide range of connectivity with long operating lifetime. Now, Electronics is widely used in information processing, telecommunication and signal processing. Due to the complex nature of electronics theory, laboratory experimentation is an important part of development of electronic devices. These experiments are used to test or verify the proposed design and detect errors. Historically, electronics labs have consisted of electronic devices and equipment located in the physical space. Although in more recent years, the trend has been towards electronics lab simulation softwares and SystemVue is also one of them. SystemVue is a focussed electronic design automation (EDA) environment for electronic system-level (ESL) design. It enables system architects and algorithm developers to innovate the physical layer (PHY) of wireless and aerospace/defence communication systems and provide unique value to RF, DSP and FPGA/ASIC implementers. As a dedicated platform for ESL design and signal processing realization, SystemVue replaces general-purpose digital, analog and math environments. SystemVue “speaks RF”, cuts PHY development and verification time in half and connects to your mainstream EDA flow.

Sign in / Sign up

Export Citation Format

Share Document