Multiferroics

Multiferroics are materials that display simultaneous ferroelectric and magnetic ordering. Due to the potential coupling of multiple order parameters, these materials are attractive platforms to study the fundamental physical processes that determine the interplay between different functional properties. They also allow for the development of new applications using multifunctional materials. Examples of multiferroics that;we are currently investigating in our laboratory include YMnO₃ and YbMnO₃ [1,2]. These systems belong to the family of hexagonal manganites, and high quality, epitaxial films have been obtained on hexagonal wide bandgap semiconductor materials, such as GaN and ZnO. The coupling of multiferroics with traditional semiconducting systems allows for integration of new functional behavior in hybrid structures for novel semiconducting device applications. 

Figure 1. Ferroelectric hysteresis loop of YMnO₃ with a coercive field of 50 kV/cm and a remnant polarization of 2 μC/cm². From Ref. [2].

[1] A. Posadas et al., Phys. Stat. Sol. B, 243: 2085, 2006
[2] A. Posadas et al., Appl. Phys. Lett., 87: 171915, 2005