Thickness effect on nanoscale electromechanical activity in Pb(Mg1/3Nb2/3)O3-PbTiO3 thin films studied by piezoresponse force microscopy

Abstract

0.7Pb(Mg 1/3 Nb 2/3 )O 3 -0.3PbTiO 3 (PMN-PT) ferroelectric thin films with thickness ranging from 28 to 110 nm were sputter deposited onto LaNiO 3 /SiO 2 /Si substrates. Optical properties were determined by spectroscopic ellipsometry. We found B ¼ 4.6 and k 0 ¼ 209 nm, which is consistent for all PMN-PT samples with previous results shown in the literature. Nanoscale electromechanical activity was probed by using piezoresponse force microscopy in imaging and spectroscopic modes. Both piezoresponse images and local piezoloops recorded on each film highlighted an enhancement of piezoelectric vibration amplitude when the film thickness increased from 28 to 62 nm ($1.06 to $1.34 mV), then saturation was observed for thicker films. This specific evolution was explained taking into account the low-permittivity interfacial Pb 2 Nb 2 O 7 layer existing between bottom electrode and PMN-PT layer. Higher leakage current when thickness is decreasing was shown, which could also explain the particular behavior of the local electromechanical properties. V

Thickness‐dependent domain wall reorientation in 70/30 lead magnesium niobate‐ lead titanate thin films

“…As discussed above, numerous factors contribute to the size effects of ferroelectric films. To support the integration of high strain relaxor‐ferroelectrics in the aforementioned devices, this work aims to identify the dominant mechanisms of thickness dependence in 70PMN‐30PT, especially at thicknesses below 600 nm where PMN‐PT can be grown crack‐free on Si . The 70PMN‐30PT films were grown by chemical solution deposition (CSD) in a thickness series from 100 to 350 nm on two different substrates.…”

“…To support the integration of high strain relaxor-ferroelectrics in the aforementioned devices, this work aims to identify the dominant mechanisms of thickness dependence in 70PMN-30PT, especially at thicknesses below 600 nm where PMN-PT can be grown crack-free on Si. [48][49][50][51] The 70PMN-30PT films were grown by chemical solution deposition (CSD) in a thickness series from 100 to 350 nm on two different substrates. Strongly {001} oriented polycrystalline films were grown on platinized Si substrates, while SrTiO 3 single crystals with SrRuO 3 bottom electrodes were employed for growth of epitaxial {001} PMN-PT.…”

Ion‐Beam Etching on Nanostructured La2Ti2O7 Piezoelectric Thin Films

“…As a result, FIB etching process affects local electrical properties of LTO thin film. By considering the relatively large thickness for the LTO layer remaining after etching (between ~148 and ~100 nm), we can exclude the influence of the thickness variation on the specific evolution of piezoelectric properties . In this spirit, we showed on Pb(Mg 1/3 Nb 2/3 )O 3 –PbTiO 3 films that a saturation in the piezoelectric vibration amplitude was obtained for film thickness higher than 62 nm.…”