Influence of the deposition geometry on structural and ferroelectric properties of epitaxial PMN-PT films

Ferroelectric 0.68Pb(Mg1/3Nb2/3)(3)-0.32PbTiO(3) (PMN-PT) films were prepared on La0.7Sr0.3CoO3 (LSCO) buffered SrTiO3 (STO) substrates by pulsed laser deposition (PLD). The influence of different deposition geometries on the structural and ferroelectric properties of the grown PMN-PT films was studied. Whereas an epitaxial growth was observed in a wide temperature range, most of the films showed a secondary phase with a pyrochlore structure in addition to the desired perovskite phase. As a result, high leakage currents were measured in these films due to the secondary phase. A pure perovskite phase growth with promising ferroelectric properties were obtained in PMN-PT/LSCO/STO film architectures deposited by on-axis PLD below 600 degrees C. The peak split of the PMN-PT (00l) reflections indicate the coexistence of different structures in these layers.