CONTEXT

Telecommunication component are generally produced with Ferro electromagnetic materials. In order to improve electronic properties of the ferroelectric material it is mixed with a low loss dielectric material very often an oxide. Traditional processes in ceramics consist in mixing two powders; other processes aim to build core shell structures (dielectric = shell). Powders are then sintered to form the component. Nevertheless structure of the composite material obtained is not controlled.

TECHNICAL DESCRIPTION

This is one aim of the invention to provide a process which allows the control of the composite material structure so that the resulting component can adjust its frequency answer  through the application of an electric field .

Such composite structure is tuned through the coating of the ferroelectric material in a SC process. Doing so the dielectric coating is finely controlled in terms of thickness, composition (no pollution in comparison with traditional methods)

Furthermore process parameters can be adjusted to produce either only coated particles or coated particles and particles of the coating material. These last improve the sintering step by filling the voids between the coated particles.

BENEFITS

– Sintering is easer and diffusion of the shell can be limited

– Avoid growth during sintering and keep size dependant properties

– High crystallised BST (>98%) without BaCO3

– Dielectric loss smaller than 1%

TECHNICAL DESCRIPTION

High frequency electronic components for emission, reception or filtering of signals like capacitors, resonators, Radar antennas

DEVELOPMENT STAGE

Various particles have been produced and sintered; electric properties have been demonstrated : Material may be PbTiO₃, PZT, PMN, LiNbO₃, KNbO₃, KTN, BaTiO₃, any composition between BaTiO₃  and SrTiO₃ and the coating may be alumina (amorphous or crystallised), zirconia, silica, TiO₂ , MgTiO₃, HfO₂, SnO₂, SnO₃, Ta₂O₅.

Samples may be produced.

For further information, please contact us (Ref 86063-01)