Multiferroic materials for sensors, transducers and memory devices (review article)

Chemical compositions and basic properties of smart
materials (ferroics, biferroics, multiferroics) are introduced in this paper.
Single phase and composite ferroelectromagnetics are characterized in detail.
Multiferroic ferroelectromagnetics are materials which are both
ferromagnetic/ferrimagnetic/antiferromagnetic and ferroelectric/ferrielectric,
antiferrolectric in the same phase. As a result they have a spontaneous
magnetization which can be switched by an applied magnetic field, a spontaneous
polarization which can be switched by an applied electric field, and often there
is some coupling between those fields. The physical mechanisms of the coupling
process were analyzed. In the case of the ferroelectromagnetics in general the
transitions method d electrons, which are essential for magnetism, reduce the
tendency for off-center ferroelectric distortion. Such materials have all the
potential applications of both their parent ferroelectric and ferromagnetic
materials.