1. The 9th international Conference for Basic Sciences
(ISCAZ)
Electric transport properties of PbTiO3
M.H. Ammar1, M.M. Elhady2, T.M. Salama3 and A.A. Bahgat2
1) Department of Basic Science, Faculty of Engineering Science, Sinai University, Al-Arish, Egypt
2) Department of Physics, Faculty of Science, Al-Azhar University, Nasr City 11884, Cairo, Egypt.
3) Department of Chemistry, Faculty of Science, Al-Azhar University, Nasr City 11884, Cairo, Egypt.
Abstract
In the present study we obtained the detailed dielectric properties of PbTiO3 ceramic. The formation of the materials was confirmed through basic structural analysis using x-rays diffraction data collected at room temperature. Dc as well as pyroelectricity measurements were conducted in the temperature range (313 to 823 K). While the Ac measurements were conducted in the frequency range (0.12 to 102 kHz). Ferroelectric phase transition have been established at 763 K. Ac conductivity behavior as a function of both temperature and frequency, showing a semiconducting like behavior. Thermal activation energy is obtained from Ac and Dc conductivity. Dielectric modulus was also studied as a function of both temperature and frequency.
Results
XRD & FTIR
dielectric properties
(a)
(b)
(c)
(a)
(b)
(a) XRD patterns of PT. (b) W-H method plot .(c) FTIR Transmittance spectra of the powder PbTiO3
(a) Real dielectric permittivity as a function of temperatures at different frequencies, (b) the loss factor as a function of temperatures at different frequencies
(c)
(d)
Dielectric modulus
(c) dielectric permittivity as a function of frequencies at a different temperature. (d) Application of the Curie–Weiss law of ferroelectricity (1/ε’r) as a function of temperature at 1KHz
The real and imaginary dielectric modulus(M’)and (M’’) dependence of the temperature and different frequencies also Curie’s temperature appears in 100kHz at 763 K
(a)
(b)
(a)
(b)
a.c and d.c conductivity as a function of reciprocal temperature, (b) relation between a.c conductivity and the frequencies as a function different temperatures.
Type R
(nm)
PbTiO3
1.08
1.29
815
1.7
2.46
1.49
(a) Relationship between the temperature and frequency at maximum peak of M’’ (relaxation part).(b) Temperature dependence of the frequency exponent (s)
Conclusion
pyroelectricity
PbTiO3 ceramic X-ray diffraction (XRD) patterns is exhibited average crystalline size D = 82 nm while the strain ε is , in addition the measurements of dielectric properties as a function of temperature in the range (313 to 823)K and at different frequencies (0.12, 1.0, 10 and 100 kHz), The observed dielectric permittivity (ε) and the loss tangent factor values of the present PT show ferroelectric behavior. The Curie’s temperature (TC) have been observed at 763 K, as well as the dielectric modulus used to tribute the relaxation frequency. Thermal activation energy is obtained from Dc and Ac conductivity at higher temperatures are found to be 1.17, and 1.08 eV, on the other hand pyroelectric coefficient π was measured and the Polarizability
The sample was poled at 23.9 V during cooling from 823 K to room temperature and then, heated from room temperature to 823 K and the pyro-current was monitored by a sensitive electrometer. Pyroelectric coefficient as a function of temperature for the PbTiO3 is shown