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The effect of Fe and Ni doping on piezoelectric properties of a soft type piezoelectric material was investigated. The materials composition was as follows: Pb 0.95 Bi 0.03 Nb 0.02 Zr 0.51 Ti 0.49-x M x O 3 , where M stands for the transitional metals Fe or Ni and x=0; 0.02; 0.04; 0.06; 0.08; 0.10. The materials were prepared by the conventional ceramic technique, using high purity oxides, mixed in a planetary ball mill for 3 hours and double calcined at 850 o C and 900 o C for 2 hours, with an intermediate milling of 4 hours and a final milling of 48 hours in order to get a final powder with crystallites in the nanometric range. X-ray diffractograms showed that compounds were completely formed and they were situated in the nanometric range with an average crystallite size of about 95 nm. The pressed and sintered samples of these materials showed maximum densification of about 98.5 % of TD at an optimum sintering temperature of 1200 o C for both types of materials. The optimum amounts of doping for both types of transitional elements were situated somewhere around x=0.06 with better results for nickel doped samples. Thus the maximum density for 0.06 nickel doped material was 7.87 g/cm 3 while for iron doped one it was only 7.80 g/cm 3 . The piezoelectric properties followed consequently the same trend. Thus the electromechanical coupling factor k p for 0.06 nickel doped samples was 0.665 while for the correspondingly iron doped ones it was 0.638. The relative dielectric constant was about 4050 for nickel doped samples and 3400 for iron doped ones. The corresponding values for the charge constant d 33 were 625 pm/V and 530 pm/V respectively. These results were discussed in terms of the positions occupied by Ni and Fe into the lattice, the type of vacancies created by this and the shift of the morphotropic phase boundary.

Structural and electrical properties of epitaxial Pb(Zr0.2Ti0.8)O3 films grown by pulsed laser deposition from targets with different purities are investigated in this study. One target was produced in-house by using high purity precursor oxides (at least 99.99%), and the other target was a commercial product (99.9% purity). It was found that the out-of-plane lattice constant is about 0.15% larger and the a domains amount is lower for the film grown from the commercial target. The polarization value is slightly lower, the dielectric constant is larger, and the height of the potential barrier at the electrode interfaces is larger for the film deposited from the pure target. The differences are attributed to the accidental impurities, with a larger amount in the commercial target as revealed by composition analysis using inductive coupling plasma-mass spectrometry. The heterovalent impurities can act as donors or acceptors, modifying the electronic characteristics. Thus, mastering impurities is a prerequisite for obtaining reliable and reproducible properties and advancing towards all ferroelectric devices.