The effects of drying temperature on the crystallization of YMnO3 thin films prepared by sol-gel method using alkoxides

In present work, we have investigated the structure and ferroelectric properties of the YMnO3 thin films on Pt(111)/Ti/SiO2/Si substrate fabricated by a sol-gel process using alkoxides. The crystal orientations and microstructures of the YMnO3 thin films were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The preferred c-axis orientation and the dielectric characteristics of YMnO3 thin films were improved by increasing the drying temperature. The ferroelectric properties such as remanent polarization were found to be dependent on the orientations of the YMnO3 thin films. As a result, the highly c-axis oriented YMnO3 thin films exhibited higher remanent polarization (2Pr=3.6 μC/cm2) compared with randomly oriented YMnO3 thin films. The dielectric constant of thin film dried at 450 °C is 19 that is close to YMnO3 single crystal. It was found that the higher drying temperature affects the ferroelectric properties due to higher crystallinity with the c-axis preferred orientation.