Ferroelectric bismuth layer oxide ceramic materials and thin films. Processing, characterization and properties

An up to date review of processing, characterization and main properties of the ferroelectric complex bismuth oxides belonging to the so-called Aurivi llius phases family is given. Processing aspects involved powder preparatio n by solid state reaction of oxides, in molten salts synthesis and sol-gel route. Bulk ceramic materials could be fabricated either by conventional si ntering or more specifically by hot forging. The sol-gel technique, which a llows to easily prepare thin films with controlled homogeneity, thickness a nd composition, is briefly described and applied to these materials. An ove rview of the principal dielectric properties is presented and focussed on t he ferroelectric and piezoelectric characteristics of bulk ceramics. Some p roperties of ferroelectric thin films, which are very good candidates for t he fabrication of ferroelectric memories, are given. Future applications of these materials are set out.