Competing functionality in multiferroic YMnO₃

We have investigated the dual functionality of multiferroic YMn O3, which simultaneously possesses antiferromagnetic and ferroelectric properties. When the YMn O3 was used as a pinning layer, it gave rise to an exchange bias and enhanced coercivity in a soft ferromagnetic film which depended on the YMn O3 crystal orientation. Significantly, the exchange bias and coercivity were minimal for the (0001) YMn O3 surface, which is optimal for ferroelectric applications. Consequently, although multiferroics, such as YMn O3, can be exploited in magnetic and ferroelectric applications independently, applications which aim to exploit their multifunctionality will be limited by the competing crystal orientations required for each application.