Study on ferroelectric domain's growth of(Pb,La)TiO_3 films by piezoresponse force microscopy

The piezoresponse force microscopy(PFM) is a useful method to study ferroelectric domains of ferroelectric films.Using PFM,the topography, OPP and IPP of(Pb,La)TiO_3 samples after annealing at different temperatures were studied,respectively.The results indicated that the topography of(Pb,La)TiO_3 films changed form conglutination to good-crystallinty and then combination together as the annealing temperature increased.The spontaneous polarization of ferroelectric films was strengthened and then weakened with the increasing of annealing temperature.In addition,the(Pb,La)TiO_3 film was mainly in a non-ferroelectric phase after annealing for 1 h at 625℃.However,the(Pb,La)TiO_3 film was mainly in an ferroelectric phase after annealing for 1h at 650℃ and 675 ℃,respectively.