Niobium-Cobalt co-doped Barium Titanate Dielectric Ceramics for Multilayered Ceramic Capacitors

Download

Niobium-Cobalt co-doped Barium Titanate Dielectric Ceramics for Multilayered Ceramic Capacitors.pdf

Date

2022-8-22

Author

Özgür, Berkay

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

256
views

374
downloads

Niobium (Nb) and Cobalt (Co) co-doped barium titanate ceramics were prepared to stabilize ferroelectric-tetragonal phase transformation of barium titanate. Preparation of ceramics started with mixing barium titanate, niobium oxide and cobalt oxide powders at predetermined concentrations varying from 1 to 3 at%. The mixing was done at wet conditions using distilled water with alumina balls at 50 rpm for 24 h in a ball mill. Then, the mixtures were compacted into 15 mm diameter and 3 mm thick disc shaped pellets by uniaxial pressing at 200 MPa. After that the discs were sintered at various temperatures ranging from 1250 to 1290 °C for various durations ranging from 30 to 120 min. Sintered pieces were characterized using XRD, SEM, EDS, and DSC characterization techniques. Electrical properties namely dielectric constant, dielectric loss and dielectric constant versus temperature were measured. Experimental results revealed that the co-doping of barium titanate with Nb and Co lead to broadening of dielectric constant peaks and temperature stability. A high dielectric constant of 3258 at 1 kHz was obtained at room temperature, along with +10% and -17% variation over temperature ranging between -30 and +150 ºC. Also, the dramatic change in crystal structure of barium titanate at 10 and 121 ºC was suppressed.

Subject Keywords

Dielectric Constant, Capacitance, Barium Titanate, Dielectric loss, Doping

URI

https://hdl.handle.net/11511/99374

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Distyryl-boradiazaindacenes: facile synthesis of novel near IR emitting fluorophores Dost, Zeynep; Atilgan, Serdar; Akkaya, Engin U. (Elsevier BV, 2006-09-04) Boradiazaindacenes with methyl substituents at 3 and 5 positions were for the first time shown to undergo efficient double condensation reactions with an aromatic aldehyde yielding a series of extended conjugation dyes. These new fluorophores have absorption maxima in the range of 650-660 nm. The dyes reported here have large quantum yields with 20 nm Stokes' shifted emission peaks. The straightforward synthesis of such red shifted BODIPY derivatives is important in relation to the synthesis of novel and us...
Palladium doped perovskite-based NO oxidation catalysts: The role of Pd and B-sites for NOx adsorption behavior via in-situ spectroscopy Say, Zafer; Dogac, Merve; Vovk, Evgeny I.; Kalay, Yunus Eren; KIM, Chang Hwan; LI, Wei; Ozensoy, Emrah (Elsevier BV, 2014-07-01) Perovskite-based materials (LaMnO3, Pd/LaMnO3, LaCoO3 and Pd/LaCoO3) were synthesized, characterized (via BET, XRD, Raman spectroscopy, XPS and TEM) and their NO (x= 1,2) adsorption characteristics were investigated (via in-situ FTIR and TPD) as a function of the nature of the B-site cation (i.e. Mn vs Co), Pd/PdO incorporation and H-2-pretreatment. NO adsorption on of LaMnO3 was found to be significantly higher than LaCoO3, in line with the higher SSA of LaMnO3. Incorporation of PdO nanoparticles with an a...
Enantioselective synthesis of 4,5,6,7-tetrahydro-4-oxo-benzofuran-5-yl acetate and 1-benzyl-4,5,6,7-tetrahydro-4-oxo-1(H)-indol-5-yl acetate using chemoenzymatic methods Demir, Ayhan Sıtkı; Caliskan, Zerrin; Sahin, Ertan (Elsevier BV, 2007-03-01) The chemoenzymatic synthesis of both of the enantiomers of pharmacologically interesting compounds such as 4,5,6,7-tetrahydro-4-oxobenzofuran-5-yl acetate (2a), 4,5,6,7-tetrahydro-4-oxo-6,6-dimethylbenzofuran-5-yl acetate (2b), and their hydroxy derivatives 3a, 3b, 1-benzyl4,5,6,7-tetrahydro-4-oxo-1(H)-indol-5-yl acetate (5), starting from 6,7-dihydrobenzofuran-4(5H)-one (la), 6,7-dihydro-6,6-dimethylbenzofuran4(5H)-one (7b), and 1-benzyl-6,7-dihydro-1 H-indol-4(5H)-one (4) are reported. Manganese(III) acet...
Electrochemical behaviour and electrochemical polymerization of fluoro-substituted anilines Cihaner, A; Önal, Ahmet Muhtar (2002-08-01) The electrochemical behaviour of three fluoro-substituted aniline monomers, 2-fluoroaniline (2FAN), 3-fluoroaniline (3FAN) and 4-fluoroaniline (4FAN), was investigated in aqueous acidic and organic media by means of cyclic voltammetry (CV) studies. Constant potential electrolysis (CPE) of the monomers in acetonitrile-water mixture (1: 1 by volume) using NaClO4 as supporting electrolyte yielded soluble polymers. The mechanism of electrochemical polymerization was investigated using in situ electron spin reso...
Dielectric properties of six different species of starch at 2450 MHz Ndife, MK; Şümnü, Servet Gülüm; Bayindirli, L (1998-01-01) Dielectric properties at 2450 MHz were determined for tapioca, corn, wheat, rice, waxymaize and amylomaize starches in granular (moisture content 1 and 13%) and in solution forms [starch-water ratio:1:1, 1:1.5, 1:2 (w/w)] at temperatures from 30 to 95 degrees C. Dielectric, properties were shown to be dependent on temperature, moisture content and starch type. The increase in moisture content increased dielectric constant and loss factor of all types of starches. Increasing temperatures decreased the dielec...

Citation Formats

B. Özgür, “Niobium-Cobalt co-doped Barium Titanate Dielectric Ceramics for Multilayered Ceramic Capacitors,” M.S. - Master of Science, Middle East Technical University, 2022.