The structure and dielectric properties of bismuth-nickel-niobium oxide based ceramics

This paper presents an investigation of the correlation between dielectric properties and microstructure and TiO2 crystalline-phase characteristics (rutile and anatase) in ZnO-TiO2-Nb2O5 system ceramics. Such ceramics were produced from powder mixtures of zinc oxide, niobium oxide and titanium oxide. Powder mixtures were compressed by pressing (100 MPa uniaxial and 300 MPa isostatic) and sintered at 1100, 1200 and 1250 °C. The sintered ceramics were characterized on the crystalline phases, density and microstructure and microwave frequencies. As for the microwave dielectric properties, dielectric constant, quality factor and thermal coefficient in the temperature range from-20 to 50 °C were measured. The results showed that the type of titanium oxide structure (rutile or anatase) causes influence on the type and quantity of crystalline phases in relative density of sintered ceramics and, consequently in their dielectric properties measurements.

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Development of Dielectric Properties of Niobium Oxide, Tantalum Oxide, and Aluminum Oxide Based Nanolayered Materials

Journal of The Electrochemical Society ◽

10.1149/1.1343106 ◽

2001 ◽

Vol 148 (2) ◽

pp. F35 ◽

Cited By ~ 83

Author(s):

Kaupo Kukli ◽

Mikko Ritala ◽

Markku Leskelä

Keyword(s):

Dielectric Properties ◽

Aluminum Oxide ◽

Niobium Oxide ◽

Tantalum Oxide

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Dielectric properties of niobium oxide film and tantalum oxide film at electrolytic niobium and tantalum capacitors

2012 ELEKTRO ◽

10.1109/elektro.2012.6225671 ◽

2012 ◽

Author(s):

Inas Abuetwirat ◽

Tomas Palai-Dany

Keyword(s):

Dielectric Properties ◽

Oxide Film ◽

Niobium Oxide ◽

Tantalum Oxide ◽

Tantalum Oxide Film

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Exotic Manganese Dioxide Structures in Niobium Oxides Capacitors

Microscopy and Microanalysis ◽

10.1017/s1431927612013153 ◽

2012 ◽

Vol 18 (S5) ◽

pp. 99-100 ◽

Cited By ~ 1

Author(s):

C. Nico ◽

M.R.N. Soares ◽

M. Matos ◽

R. Monteiro ◽

M. P. F. Graça ◽

...

Keyword(s):

Cost Effectiveness ◽

Dielectric Properties ◽

Shell Structure ◽

Niobium Oxide ◽

Good Alternative ◽

Grain Structure ◽

Electrolytic Capacitor ◽

Core Shell ◽

Niobium Oxides ◽

Core Shell Structure

The production of a Tantalum solid electrolytic capacitor requires the impregnation of MnO2 by pyrolysis in one of the several manufacturing steps. It has been reported that niobium oxides are a good alternative, presenting potentially better dielectric properties and a better cost effectiveness. Thus, it is important to study the conditions and the effect of the MnO2 impregnation on niobium oxide in order to understand and optimize the parameters of this process. The morphology and microstructure of the anode is one of the most important aspects that interfere with the dielectric properties of the capacitor. In this work, it is presented a study of the morphology and microstructure of different niobium oxide anodes after electrochemical oxidation (NbO/Nb2O5 core-shell grain structure), and after MnO2 impregnation with different pyrolysis temperatures. This impregnation is made by dipping the anodes, with the NbO/Nb2O5 core-shell structure, in a slurry of Mn(NO3)2. Heating this slurry while the anode is dipped, will lead to a pyrolysis reaction where the liberation of NO2 occurs as a gas, and where the product MnO2 solidifies around the grains.

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Effect of Sintering Time on Dielectric Properties of Barium Titanate and Nb Doped Barium Titanate

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.860.129 ◽

2016 ◽

Vol 860 ◽

pp. 129-133 ◽

Cited By ~ 2

Author(s):

M.K. Rahman ◽

M.F. Hossain ◽

Kazi Mohammad Shorowordi ◽

M.A. Matin

Keyword(s):

Dielectric Constant ◽

Dielectric Properties ◽

Barium Titanate ◽

Room Temperature ◽

Niobium Oxide ◽

Dielectric Material ◽

Multilayer Ceramic Capacitors ◽

Sintering Time ◽

High K ◽

Room Temperature Dielectric Constant

Barium titanate (BaTiO3) with its perovskite structure is a promising dielectric material for many applications such as transducers, actuators, high-k dielectrics and multilayer ceramic capacitors (MLCC). In this study, we have investigated the effect of sintering time on dielectric properties of BaTiO3 and Nb-doped BaTiO3. BaTiO3 was doped with 0.3 mol % niobium oxide (Nb2O5). At first, nanosized pure BaTiO3 and Nb2O5 doped BaTiO3 were milled, dried and pressed into pellets to prepare green samples. Then, the samples were sintered at 1275°C for different time periods ranging from 2 to 5 hrs. Single stage sintering was adopted for the densification of prepared samples. Microstructure of the sintered samples was investigated employing Field-emission scanning electron microscope (FESEM). Dielectric properties of the samples were measured using an impedance analyzer. Finally, a correlation was established between the dielectric properties of the sintered samples and their microstructure. Nb has shown to provide strong inhibiting effect after sintering the samples in the range of 2 to 5 hours at 1275°C thereby, resulted in higher dielectric properties of doped BaTiO3 ceramics compared to that of pure BaTiO3. The best room temperature dielectric constant of 7200 was obtained for Nb doped BaTiO3 sintered at 1275°C for five hours. Such improved dielectric constant is attributed to the optimum grain size of about 1 micron at this sintering temperature.

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