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Project ID: G5RD-CT-2001-00456
Finanziato nell'ambito di: FP5-GROWTH
Paese: Switzerland

PMN-PT thick films on alumina substrate

Inks have been optimised with different solid solutions of lead magnesium niobate - lead titanate: (1-x)Pb(Mg1/3Nb2/3)-xPbTiO3 (with x=0.1, 0.3, 0.35, 0.4, 0.5, 0.6) without sintering aids. They have been prepared from micro-powders synthesised by Ferroperm and one from nanopwders elaborated by Thales (only one composition 0.65Pb(Mg1/3Nb2/3)-0.35PbTiO3.).

A sintering study have been carried out, at high temperature for pure composition of PMN-PT, to optimise the influence of heating rates, dwell temperature / time, atmosphere on the densification and the grain growth. Pyrochlore-free PMN and PMN-PT thick films were successfully obtained by screen printing. The best thick films densification was obtained with a heating rate of 9 to 12°C/min and a sintering temperature between 1170 and 1210°C. The choice of sintering temperature was chosen according to the PT content in the relaxor-ferroelectric.

The maximum relative permittivity for PMN film was 11000, which is lower than in bulk ceramics (18000) prepared under the same conditions. For 0.65PMN-0.35PT, the maximum relative permittivity was around 15500 against 24000 in the bulk. Several parameters, which might be responsible for the lower permittivity, are discussed. Poled 0.65PMN-0.35PT thick films prepared from Ferroperm’s micropowder exhibit relatively large piezoelectric response (d33 up to 200pm/V) and unipolar strains approaching 0.1%, making these films of interest for various actuator and transducer applications.


Nava SETTER, (Director)
Tel.: +41-216932961