Fabrication of pure-perovskite PMN-PT thin films on SrTiO_3 substrates using pulsed laser deposition

摘要

Lead magnesium niobate-lead titanate ((1-x)Pb(Mg_(1/3)Nb_(2/3))O_(3-x)PbTiO_3 (x=0.20,0.33,0.50), PMN-PT) thin films have been successfully deposited on SrTiO_3(100) substrates by pulsed laser deposition (PLD). The result of X-ray diffraction (XRD) showed that the PMN-PT thin films were c-orientated. The effects of deposition conditions, such as deposition temperature, deposition oxygen pressure, pulsed laser repeated frequency, cooling rate, pulsed laser energy and post annealing, were studied first on thin-film quality. It was found that the deposition temperature was very different for the different mole fractions of the thin films. The range of the deposition temperature of high-qualitied thin films is very narrow, about ± 2 ℃. Such harsh conditions are rare in other thin films, which is also the main reason why PMN-PT thin films are very difficult to prepare.