Magnetoelectricity in multiferroically composed multilayers and multiglasses

Abstract Single-crystalline magnetoelectric (ME) antiferromagnetic Cr 2 O 3 exchange coupled to a ferromagnetic multilayer (Pt/Co/Pt) n , n ⩾1, represents a multiphase multiferroic material with sophisticated multifunctional properties. They comprise the possibility of switching the exchange bias (EB) of the ferromagnetic hysteresis loop via the linear ME effect of Cr 2 O 3 , and to design MERAM and logic cells operating at room temperature. Quadratic and cubic ME effects – promoted by soft-mode quantum fluctuations – are observed at lowest order in ceramic Sr 0.98 Mn 0.02 TiO 3 at low temperatures. Dipolar and spin glass orders occur simultaneously on the Mn 2+ subsystem and form a multiglass by analogy with conventional multiferroics.