Magnetic switch of polarization in epitaxial orthorhombic YMnO3 thin films

We report on the growth and characterization of epitaxial thin films of orthorhombic YMnO3. It is found that a ferroelectric polarization exists along c-axis (P-c similar to 90 nC/cm(2)) and a magnetic field induces the development of a ferroelectric polarization along a-axis (P-a) while suppressing P-c. This field-induced switching is consistent with the existence of a cycloidal magnetic order in YMnO3. This finding evidences that a noncollinear spin arrangement in thin films allows switchable electrical polarization and of tunability of their dielectric response by magnetic field. (C) 2010 American Institute of Physics. [doi:10.1063/1.3523352]