Colloquium on April 28th, 2008
Jeroen van den Brink
Novel routes to Multiferroics
As this new century unfolds the study of materials possessing coupled magnetic and ferroelectric order multiferroics is revitalized, after pioneering work in the 1950s-1960s [1,2]. New classes of materials were found to be ferroelectric and exhibiting an exceptionally strong sensitivity to applied magnetic fields. These multiferroics show many dramatic effects, such as a giant magneto-capacitance, magnetically induced electric polarization flops and a rotation of electric polarization in a periodically varying magnetic field [3-5]. These effects are not only interesting from a fundamental point of view but can also be directly relevant for sensor, transducer and memory device applications . This motivated Science Magazine a few months ago to identify the field of multiferroics as an Area to Watch . In the colloquium I will discuss new theoretical possibilities to obtain multiferroic couplings in systems that exhibit combinations of charge and spin order [6-10].
 N. Spaldin and M. Fiebig, Science 309, 391 (2005).