Electric-Field Controlled Magnetism
This chapter focuses on the electric-field effects on magnetism, as well as the electric-field control of magnetization dynamics and direction. It describes the electric-field effect-related phenomena in magnetic semiconductors and metals. The effect was first demonstrated using ferromagnetic semiconductors, and is observed in other material systems, that is, metals and multiferroics. One of the most important characteristics of magnetic semiconductors is that the magnetic order is brought about by the presence of carriers. Stimulated by studies on magnetic semiconductors, researchers began to investigate electric field effects in metals. The magnetization measurements revealed that the electric fields modulate the magnitude of spontaneous magnetic moment, in addition to TC due to the change in the surface depletion layer thickness. The electric field modulation of the in-plane magnetic anisotropy was also observed through the transverse component of anisotropic magnetoresistance effect, sometimes referred as the planar Hall effect.