Ferroelectric properties of YMnO3 thin films prepared by chemical solution deposition

The YMnO3 thin films were prepared on platinized silicon substrates by chemical solution deposition. The films were crystallized by annealing at 850 degreesC for 1 hour under various atmospheres, i.e., O-2, air, Ar, and vacuum. Effects of annealing atmospheres on the crystallization behavior and electrical properties were investigated. Crystallization behavior of an YMnO3 thin film critically depended on the oxygen partial pressure of the annealing atmosphere. The YMnO3 thin film annealed in Ar showed a superior crystallinity and a strongest c-axis preferred orientation. Leakage current density decreased with lowering oxygen partial pressure of the annealing atmosphere. The C-V and P-E ferroelectric hysteresis were found only in the YMnO3 thin film annealed under Ar atmosphere. Leakage current density, dielectric constant(epsilon (r))(,) remanent polarization(P-r) and coercive field(Ec) of the film annealed in Ar were 1.7x10(-8) A/cm(2) at 1 volt, 25, 1.08 muC/cm(2), and 100 kV/cm, respectively.