Phase evolution of electron-beam evaporated Pb(Zr,Ti)O3 thin films

Solid phase reactions among electron-beam deposited PbO, ZrO2 and TiO2 in the thin film state as distinct from those occurring in the bulk state are described under varied annealing conditions leading to growth of perovskite PZT phase. Loss of PbO by direct high temperature (700 °C) anneal led to the growth of cubic A2B2O7−x pyrochlore as well as an AB3O7 phase of monoclinic structure. A lower temperature initial anneal at 600 °C in O2 ambient minimises PbO loss through phase transformation to tetragonal Pb3O4 and better crystallised oxide phases partially react to form pyrochlore as well as perovskite PZT. This partial reaction is kinetically driven as it goes to completion in ∼4 h resulting in transformation of pyrochlore to perovskite phase. At high temperature (800 °C) A2B2O7−x phase converts to PZT perovskite and the AB3O7 dissociate to yield TiO2 secondary phase inclusion in the PZT film.