Study of the relaxor behaviour in Ba0.68Na0.32Ti0.68Nb0.32O3 ceramic

• Autorzy: Bąk, W.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The purpose of this work was to synthesize a new ceramic solid solution Ba0.68Na0.32Ti0.68Nb0.32O3 (BNTN32), as well as to measure and analyse its dielectric properties within the temperature range 123 K-473 K, where dielectrically active phase transition was supposed to occur. Design/methodology/approach: The new ceramic composition was prepared by means of conventional method. Dependence of phase transition features on temperature and frequency of measuring field were measured using dielectric spectroscopy method within the frequency range from 20 Hz to 1 MHz. Findings: The electric susceptibility along with temperature decrease generally rises up and has transient dispersion vanishing at about 230 K. At higher and low temperatures, frequency dependence of dispersion differs in character: at temperatures at ~400 K, low frequency values dominate. Dielectric energy losses are very high at ~high temperature, they decline down while temperature decrease, and at about 200 K range its frequency dependence is reversed and less scattered with maximum at ~150 K. The whole transition of ferroelectric - paraelectric (FE - PE) type can be described by means of Curie-Weiss law and it gets diffused character. Research limitations/implications: For modelling purposes the structure parameters of BNTN32 have to be measured by X-ray diffraction in order to establish the dielectric/structural activities of transitions taking place within used the temperature range. Additionally, dielectric measurements within broader frequency range up to 1.8 GHz will be performed. Originality/value: The new type of ceramic material was prepared with interesting dielectric properties. Dispersion reverse of energy losses activated thermally and low frequency memory of barium titanate (BT) transition effect visible at ~400 K is to be a subject of modelling further work.

Słowa kluczowe

PL

polikryształ; przemiana fazowa; ferroelektryki; relaxor; spektroskopia dielektryczna

EN

polycrystals; phase transition; ferroelectrics; relaxor; dielectric spectroscopy

• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2009
• Tom: Vol. 37, nr 1
• Strony: 24-27
• Opis fizyczny: Bibliogr. 16 poz., rys., tabl.

Twórcy

autor

Bąk, W.

• Institute of Physics, Pedagogical University, ul. Podchorążych 2, 30-084 Kraków, Poland,

Bibliografia

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• [5] W. Bąk, C. Kajtoch, F. Starzyk, J. Żmija, Evolution of electric polarization in paraelectric phase of BaTiO3, Archives of Materials Science and Engineering 33/2 (2008) 79-82.
• [6] W. Bąk, Relaxor properties of Ba1-xNaxTi1-xNbxO3 at low temperatures, Archives of Materials Science and Engineering 34/1 (2008) 23-26.
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• [16] F. Starzyk, Parameterisation of interdigit comb capacitor for dielectric impedance spectroscopy, Archives of Materials Science and Engineering 34/1 (2008) 31-34.