Abstract:
A ferroic material is one which can, or can be conceived to, undergo one or more
ferroic phase transitions. A phase transition is called a ferroic phase transition if:
(a) it can be viewed as a nondisruptive modification of a certain “prototypic phase”,
and (b) it involves a loss of one or more point-symmetry operators present in the
prototype. By “nondisruptive modification” it means that the new phase can be
described by it’s symmetry elements, Wyckoff positions, atomic parameters, etc., in
the frame of reference of the other phase, after making continuous distortions that
do not themselves entail any additional change of symmetry [1]. Ferroic materials
are being used in many technological applications. Ferroics is the generic name
given to the study of ferromagnets, ferroelectrics, and ferroelastics. This chapter
deals the main aspects of ferromagnets, ferroelectrics and multiferroics.
