RECENT PROGRESS ON FERROELECTRIC CERAMICS

Ferroelectric ceramic components such as multilayer ceramic capacitors (MLCC), piezoelectric resonators have played important roles in evolution of advanced electronics.  Size reductions of these components have allowed highly integrated functional electronic devices such as cellular phones.  Size reduction of an MLCC has resulted in an electric field increase applied to each layer.  High resistance to higher electric field is eagerly required for the MLCC more than before. 
On the other hand, ferroelectric ceramics have been widely used also in various electromechnical devices, sensor or actuator devices as so-called human-machine interfaces.  Piezoelectric ceramic components have been key materials there, however, typical piezoelectric ceramics are Pb-based ones which are preferably alternated by Pb-free materials.  
The demands for further integrated functional devices will necessitate higher reliability against applied electric fields, environmentally safe compositions, and so on, as well as higher performances or functionalities to the ferroelectric ceramic materials used for both bulks and thin films.  In this paper, we give a review of current status of ferroelectric materials R&D trends, and their future perspectives.