Crystallization Study of the Alkoxide-Based Pb(Zr0.30Ti0.70)O3 Thin-Film Precursor

Barbara Malič, Jena Cilenšek, Mira Mandeljc and Marija Kosec
Institut Jožef Stefan, Jamova 39, 1000 Ljubljana, Slovenija,

Thermal decomposition and crystallization of the alkoxide-based precursor for Pb(Zr0.30Ti0.70)O3  thin films by chemical solution deposition (CSD) method is studied by a combination of thermal analysis methods and X-ray diffraction. The precursor was prepared from lead oxide and zirconium and titanium n-butoxides in 2-methoxyethanol and dried at 60 °C. Thermal decomposition takes place stepwise: solvent evaporation is followed by the organic-group decomposition between 200 and 440 °C, carbonate-group removal and crystallization between 440 and 600 °C. The crystallization of the thermodynamically stable perovskite phase that occurs through the transitory pyrochlore-type phase, was followed by differential thermal analysis; in this case the sample was precedingly heated at 400 °C. The crystallization of the perovskite phase is exothermic, with enthalpy equal to 33 kJ/mol.
In the case of the Pb(Zr0.30Ti0.70)O3  thin film deposited on Pt(111)/Si substrate the crystallization temperature of the perovskite phase is further decreased as a consequence of the heterogeneous nucleation on the platinum surface: pure perovskite phase is obtained at as low as 400 °C. The crystallization of (111) oriented perovskite phase occurs directly from the amorphous phase.

Key words: Pb(Zr0.30Ti0.70)O3, alkoxide, thin films, thermal analysis, crystallization.