Fabrication of La2Ti2O7 nanostructures by focused Ga3+ ion beam and characterization by piezoresponse force microscopy.

(012)-oriented lead-free La2Ti2O7 thin films with the monoclinic/perovskite layered structure have been grown by a solgel route on (100)-oriented doped Nb:SrTiO3 substrates. On nanoscale, both poling experiments performed via the tip of atomic force microscope and the existence of local piezoloops within the domains confirm the piezo-/ferro-electric behaviour of the films. Islands in the lateral range 300–500 nm have been fabricated by focused Ga3+ ion beam etching on platinum top electrode. As measured on piezoloops, electromechanical activity within the islands is shown to be similar to the one obtained for the virgin film; no piezoelectric degradation for La2Ti2O7 islands is highlighted. These results confirm that La2Ti2O7 is a highly resistant oxide to ion-beam irradiation. La2Ti2O7 could be considered as a material of choice for the realization of lead-free piezoelectric nanostructures. [ABSTRACT FROM PUBLISHER]