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Nanoporous and dense ferroelectric PbTiO 3 thin films are prepared by a modified solgel process. The presence of nanoporosity, with ~ 50 nm pore size formed using a block polymer as a structure-directing agent, markedly affects the microstructure, crystallization and ferroelectric film´s properties. The crystallization of the tetragonal phase is enhanced in nanoporous films. It is suggested that the decomposition of the block-copolymer in porous films triggers the crystallization of the perovskite phase at low temperatures via the local increase of temperature. Consequently, nanoporous films with improved tetragonality exhibit enhanced piezoelectric coefficients, switchable polarization and low local coercivity. By providing a means of achieving enhanced properties, nanoporosity may have a broad impact in applications of ferroelectric thin films.Nanoporous PbTiO 3 films present enhanced tetragonality at lower temperature than respective dense films. Moreover, the porosity present in the nanoporous films allows an increase of the local piezoelectric response and a decrease of the local coercive field. As result, these nanoporous films might be used to improve switching behaviour of ferroelectric thin films

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