Ferroelectric property of alkoxy-derived YMnO3 films crystallized in argon

Stoichiometric YMnO3 films were synthesized by spin coating an alkoxy-derived precursor solution and rapid thermal annealing at 750degreesC in argon. The YMnO3 film crystallized on the Pt/TiOx/SiO2/Si substrate had a high crystallinity and high degree of c-axis orientation. It was confirmed that the composition and Mn valence state of the film did not change during the annealing in an Ar atmosphere. No interface layer was observed between the YMnO3 film and substrate. The YMnO3 film had a uniform and dense microstructure and consisted of well developed large grains of which the diameter was approximately 150-200 nm. The dielectric constant and loss tangent of the 400 nm-thick YMnO3 film were 25.5 and 0.017, respectively, at 100 kHz. The remanent polarization and coercive field at the applied voltage of 20 V were 2.2 muC/cm(2) and 110 kV/cm, respectively.