Pulsed laser deposition of PMN thin films

Lead magnesium niobate (Pb(Mg1/3Nb2/3)O-3 or PMN) thin films have been deposited on different substrates by pulsed laser deposition. Film composition was studied by secondary ion mass spectroscopy and their crystallinity by Xray diffraction techniques. Small-signal dielectric constant and loss factor of the films have been measured as a function of temperature and frequency on structures with 3 mm diameter evaporated An top electrodes, by using an impedance analyser. The obtained PMN films have been found polycrystalline and partially oriented, with a certain amount of secondary pyrochlore phases and interface phases which are detrimental for the overall dielectric constant and modifies the behaviour of the heterostructures. Polarization hysteresis measurements performed at different temperatures below and above the dielectric maximum temperature T-m showed the persistence of polarization above T-m. (C) 2002 Elsevier Science Ltd. All rights reserved.