Recent advances in integrated ferroelectric and multiferroic materials

Ferroelectric materials have very appealing properties such as their dielectric permittivity, piezoelectric coefficients and permanent polarization. Two large scale applications of ferroelectric thin films are already achieved: on-chip large capacitances (MIM) and Ferroelectric Random Access Memories (FERAM). The focus is now on the design and reliability of integrated structures. The case of high frequency agile capacitors based on ferroelectric films will be described in details in this respect. Multiferroic materials are under consideration since more than 50 years because of the coexistence and eventually the coupling between polarization and magnetization in a given compound. Since the number of room temperature multiferroics is very restricted at present, several alternative routes including nano-composites or multilayers are under consideration.