Investigations of Al1-xGaxFeO3 family of oxides

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.