الفهرس 
Piezoelectric Parameters and RelationsOnly 14 pages are availabe for public view
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Abstract
BaTiO3 -PbTiO3 nanocomposite materials with formula (1-x) – (x) where x=0-0.2-0.4-0.6-0.8 and 1 were prepared using tartaric acid method . The x-ray diffraction patterns for the nanocomposite (1-x) – (x) synthesized by the chemical reaction using the tartaric acid has been studied. The lattice constants for BaTiO3 are increased by increasing PbTiO3 up to (x 0.4 ). The average crystallite size lies in nanometer range . FTIR spectral analysis of composites were measured at room temperature and the spectra were recorded from 200 to 1000 cm -1. The spectra shows two vibration peaks . The study of Scanning Electron Microscope and Transmission Electron Microscope confirmed the results of the XRD. The thermogravimetric analysis (TGA) for the samples showed a weight loss in three phases The DC resistivity versus temperature for pure BaTiO3 and PbTiO3 has been studied , BaTiO3 shows higher values of resistivity , and also shows positive temperature coefficient of resistivity (PTCR) effect for samples sintered at 900 ᵒC for 4 hours , It was observed that the resistivity decreases at high temperatures . The dielectric behavior of pure BaTiO3 gives a curie temperature at 116 ᵒC which corresponds to phase transition from tetragonal to cubic. with increasing PbTiO3 content,the curie temperature shifts to a higher temperature .The dielectric constant of the composite samples is higher than pure BaTiO3 but shows a minimum when PbTiO3 concentration is 0.8.In general , permittivity Ԑ increases with the increase in PbTiO3 concentration due to high permittivity PbTiO3 material . The dissipation factor, tan δ of the composite samples is lower than BaTiO3 samples. The variation of tan δ with temperature is more stable for the 116 sample (x=0.2) lead titanate .The dielectric loss was found to increase by increasing temperature for the composite samples. For the composite samples (x ) tan δ shows temperature independent up to 500 ᵒk. The behavior of dielectric loss is nearly similar to that of dielectric constant. The dielectric loss decreases by increasing PbTiO3. The AC resistivity decreases with the increase in frequency, this might be due to at lower frequencies the charge carriers have not enough energy to outruns the high energy barriers so the charge carriers contributing to conductivity have high relaxation time, this may be resulting in higher resistivity as the frequency increases more charge carriers have enough energy to overcome the barrier height resulting in lowering resistivity. The increase in AC resistivity with increasing temperature indicate the positive temperature coefficient of resistance (PTCR) character. The piezoelectric coefficient d33 for the composite samples shows the effect of PbTiO3 addition on the piezoelectric modulus d33.It is found that the d33 increases with increasing x (content) up to x 0.4. After that the d33 decreases. For the ferroelectric hysteresis loop, it is noticed that the coercive electric field (Ec) decreases as the grain size increases, Energy barriers for switching ferroelectric domains must be broken through and decreases as grain size increases .So unusual polarization process of ferroelectric domain is much easier inside a large grain than in a small grain.