Czasopismo
2008
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Vol. 33, nr 2
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75-78
Tytuł artykułu
Autorzy
Wybrane pełne teksty z tego czasopisma
Warianty tytułu
Języki publikacji
Abstrakty
Purpose: Purpose of this work was to determine crystalline structure and ac electric conductivity of polycrystalline sample Pb(Cd1/3Nb2/3)O3 (PCN) in paraelectric phase. Controversies involving uncertainties of phase transition character were the motivation of our experimental investigation: roentgenostructural, electron microscopy (SEM) and dielectric (ε') as well as electric (δ') spectroscopy. Design/methodology/approach: Polycrystalline PCN samples were prepared using hot pressing method. X-ray measurements had been performed with use of DRON3 apparatus (Cu Kα, monochromator: monocrystal LiF, at detector NaI side) with jump of 2O angle accounting for 0.02deg within a range 10-120deg. Structure images were made at room temperature with a use of electron microscope Philips SEM 525M. Dielectric measurements were made with a use of automatic measuring system Quatro Cryosystem 4.0 and Agilent Precision LCR meter HP4284A equipped with WinDETA 5.62 software Novocontrol. Before measurements, polycrystalline PCN samples were refreshed by annealing at 700 K. Next, electric measurements were carried out under cooling with 2 K/min speed. Findings: It was established that cubic phase is present within the whole range of temperatures (173 K-723 K) applied in our measurements. The polar component of the electric conductivity was dominate below the Tm temperature (Tm - temperature at which the maximal value of dielectric permittivity takes place). Above this temperature, activation energy (φ) is falling down, along increasing frequency of measuring field. Research limitations/implications: Changes of AC conductivity of PCN were interpreted in terms of polar regions properties evolution. Originality/value: Results obtained have broad the knowledge about phase transitions occurring without crystal structure change, but involving freezing of polar regions under cooling.
Rocznik
Tom
Strony
75-78
Opis fizyczny
Bibliogr. 15 poz.
Twórcy
autor
autor
autor
autor
- Institute of Physics, Pedagogical University, ul. Podchorążych 2, 30-084 Kraków, Poland, ckajtoch@ap.krakow.pl
Bibliografia
- [1] Landolet-Boersnstein, New Series 3, Vol. 3, Springer-Verlag, Berlin-Heidelberg-New York, 1969.
- [2] J. Ravez, A. Simon, Non-Stoichiometric Perovskites Derived from BaTiO3 with a Ferroelectric Relaxor Behaviour, Physica Status Solidi A 178 (2000) 793-797.
- [3] A. Simon, J. Ravez, Relations between relaxor and cationic substitution in lead-free BaTiO3 derived ceramics, Ferroelectrics 240 (2000) 335-342.
- [4] C. Kajtoch, K. Wójcik, Diffuse phase transition in Pb(Cd1/3Nb1/3)O3, Acta Universitatis Wratislaviensis 1084 (1988) 155-158.
- [5] L.E. Cross, Relaxor ferroelectrics: An overview, Ferroelectrics 151 (1994) 305-320.
- [6] G. Burns, F.H. Dacol, Polarization in the cubic phase of BaTiO3, Solid State Communication 42 (1982) 9-12.
- [7] N. Ichinose, Y. Yokomizo, T. Takahashi, The behavior of the micro domains on the diffuse phase transition ferroelectrics, Acta Crystallographica A 28/4 (1972) 187-190.
- [8] C. Kajtoch, Electric properties of polycrystalline Pb(Cd1/3Nb1/3)O3, Ferroelectrics Letters 25 (1999) 81-85.
- [9] C. Kajtoch, W. Bąk, F. Starzyk, M. Gabryś, Study of phase transition specific in polycrystalline Pb(Cd1/3Nb1/3)O3, Archives of Materials Science and Engineering 29/1 (2008) 20-23.
- [10] A.K. Jonscher, Dielectric relaxation in solids, Chelsea Dielectric Press Ltd, London, 1983.
- [11] R. Comes, M. Lambert, A. Guinier, The chain structure of BaTiO3 and KNbO3, Solid State Communication 6 (1968) 715-719.
- [12] A. Buchacz, Influence of piezoelectric on characteristics of vibrating mechatronical system, Journal of Achievements in Materials and Manufacturing Engineering 17 (2006) 229-232.
- [13] A. Buchacz, A. Wróbel, Piezoelectric layer modelling by equivalent circuit and graph method, Journal of Achievements in Materials and Manufacturing Engineering 20 (2007) 299-302.
- [14] W. Bąk, F. Starzyk, C. Kajtoch, E. Nogas-Ćwikiel, Elevated temperature induced dispersion phenomena in Ba1xNaxTi1-xNbxO3, Archives of Materials Science and Engineering 29/1 (2008) 5-9.
- [15] F. Starzyk, W. Bąk, C. Kajtoch, M. Gabryś, Influence of electric field DC-component on AC-response of ferroelectric powder, Archives of Materials Science and Engineering 29/1 (2008) 36-39.
Typ dokumentu
Bibliografia
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Identyfikator YADDA
bwmeta1.element.baztech-article-BSL7-0033-0011