Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Feasibility of textured ceramics (Process)

Textured PMN-PT ceramics were synthesized by homo-template grain growth (HTGG) using PMN-PT nano-particles and cubic single crystal templates

- PMN-PT:Mn doped powders prepared by solid state reaction were milled using micro beads to reduce the grain size. Nano powders were obtained directly after high energy milling.

- Seeds of PMN-PT ranging from 50 to 100 mm were obtained by flux method. Perfect cubic crystals of 50x50x50 mm were selected as templates.

- Nano particles of PMN-PT: Mn and few wt.% of templates were mixed with organic binder to obtain homogenous slurry. Two percent excess of PbO was added in certain compositions. The mixture was tape cast using the doctor blade technique to obtain tapes of 100-150mm thick. Green tapes were dried, cut and laminated into samples of 0.5 to 3mm thickness.

- Tape stacks were sintered between 1150 and 1200°C for different durations in PbO controlled atmosphere.

Textured Tape Cast Ceramics display quasi complete (001) texture (f=0.99) in the cubic phase. The (111) pole figure reveals (001) fiber texture in accordance with optical observation. The texture was obtained in all the volume and only small orientation distribution (<6°) was observed. Smart Raman imaging shows that the final composition is very close to that of the matrix.

Piezoelectric properties measured at low level using RIE method show that coupling efficiency of tape cast textured ceramics (kp =0.69, d33= 600pC/N) are about twice of tape cast random ceramics and ~20% better than random optimised disk ceramic.

Reported by

Thales Research & Technology
Domaine de Corbeville
91404 Orsay
See on map