Domain structure sequence in ferroelectric Pb ( Zr 0.2 Ti 0.8 ) O 3 thin film on MgO

The structural evolution of a polydomain ferroelectric Pb ( Zr 0.2 Ti 0.8 ) O 3 film was studied by temperature-dependent x-ray diffraction. Two critical temperatures were evidenced: T * = 740 K , corresponding to a change in the domain structure ( a ∕ c ∕ a ∕ c to a 1 ∕ a 2 ∕ a 1 ∕ a 2 ), and T C film = 825 K , where the film undergoes a ferroelectric-paraelectric phase transition. The film remains tetragonal on the whole range of temperature investigated. The evolutions of the domain structure and lattice parameters were found to be in very good agreement with the calculated domain stability map and theoretical temperature-misfit strain phase diagram, respectively.