Structure and ferroelectric properties of ferroelectromagnetic YMnO3 thin films prepared by pulsed laser deposition

Ferroelectromagnetic YMnO3 thin films have been deposited on Pt/TiO2/SiO2/Si substrates by pulsed laser deposition technique. It is found that only these films deposited in 10-3 Pa O2 and annealed in N2 ambient were well crystallized to a hexagonal YMnO3 single phase. Furthermore, the crystallization texture of YMnO3 thin films significantly depends on the post-annealing method. YMnO3 thin film with (004) preferred orientation was fabricated by crystallizing an amorphous YMnO3 film deposited at 650 C using a rapid thermal annealing process. This c-oriented YMnO3 film shows an excellent ferroelectric polarization with remanent polarization (2Pr) of 0.52 μC/cm2 at an applied electric field of 300 kV/cm, whereas the film crystallized by conventional furnace annealing is (110) oriented and shows a poor ferroelectric polarization. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)