First principles investigation of magnetic ferroelectrics
Claude Ederer (Dept. of Physics, Columbia University, N. Y.)

Abstract: Materials that exhibit coexisting magnetic and ferroelectric order, so called magneto-electric multiferroics, are very promising for future applications in digital data storage and sensor technologies. On the other hand such materials are relatively rare, due to an apparent competition between the mechanisms favoring magnetism and ferroelectricity. However, recent progress in both experimental and theoretical/computational techniques have triggered a substantial increase of research activity in the field of magneto-electric multiferroics. In this talk I will give a brief overview over the current status and future challenges in multiferroics research, and I will show how we have successfully used electronic structure calculations based on density functional theory to address various important aspects of multiferroic materials.

In particular I will show how an experimental controversy about the magneto-electric properties of the room temperature multiferroic bismuth ferrite could be resolved, and I will discuss the possibility of manipulating magnetic order parameters using an electric field. In addition, I will touch on the exploration of alternative mechanisms for ferroelectricity that are compatible with the simultaneous presence of magnetic order, and I will point out the possible computational design of new multiferroic materials with unprecedented properties.