Abstract:
Ferromagnets, ferroelectrics, and ferroelastics all together come under a generic name
‗Ferroics‘. Studies on ferroics mainly focuses on the change of different physical properties such
as magnetic, dielectric and other related properties due to a change of external stimuli like
temperature, magnetic field, electric field etc. Often the changes of physical properties are
associated with structural phase transition at some critical temperature. This phase transitions
result in only small deviations from the nonferroic crystal structure and also alters the point
symmetry of the material. This breaking of symmetry is physically what allows the formation of
the ferroic phase. Ferroelectric materials possess a spontaneous polarization that is stable and can
be switched hysteretically by an applied electric field where as ferromagnetic materials possess a
spontaneous magnetization that is stable and can be switched hysteretically by an applied
magnetic field and ferroelastic materials display a spontaneous deformation that is stable and can
be switched hysteretically by an applied stress. In recent years a new class of novel ferroic
materials, called multiferroics which exhibit more than a single ferroic property simultaneously
in a single phase has drawn considerable attention of the researcher. This chapter deals with main
aspects of ferromagnets, ferroelectrics and multiferroics.
