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Characterisation of newly obtained Pb(Mn1/3Nb2/3)O3 ceramics by XRD, XPS and dielectric permittivity tests.
|Aleksander Molak , Ewa Talik , Magdalena Kruczek , Alicja Ratuszna , Marian Paluch|
University of Silesia, Katowice, Poland
The Pb(Mn1/3Nb2/3)O3 ceramics has been newly obtained from oxides by sintering in air, using a two-step process with precursor phase. In the first step, the columbite-like phase, (Mn0.5Nb)O3 was obtained. Lead oxide was added in the second step. The final sintering temperature was equal to 1150 oC. Analysis of the XRD spectra indicates that the ceramics consThe cell parameters are: a = 12.193(3) Å, b =11.966(6) Å, c = 12.144(2) Å beta = 90o10.7'. X-ray photoelectron spectroscopy was used to study the chemical composition and electronic structure of the Pb(Mn1/3Nb2/3)O3 ceramics. A nominal chemical composition was Pb1.00(Mn0.33Nb0.67)O3 while the chemical composition obtained from the XPS measurements is Pb0.99(Mn0.43Nb0.67)O2.92. The core levels of lead, manganese, niobium and oxygen were measured and deconvoluted into the synthetic peaks. Broadband dielectric measurement was carried out in frequency range from 10-2 to 106 Hz within 90 - 600 K temperature range. From analysis of dielectric spectra two relaxation processes were distinguished. First process, manifesting at lower temperature range, is related to electric conductivity with activation energy, Ea = 0.35 eV. The second process exhibits relaxation properties characteristic for a diffused, relaxor-type phase transition.
Presentation: poster at E-MRS Fall Meeting 2004, Symposium I, by Ewa Talik
See On-line Journal of E-MRS Fall Meeting 2004
Submitted: 2004-05-27 11:56 Revised: 2009-06-08 12:55