Lead-free (K0.5Na0.5)NbO3 thin films by pulsed laser deposition driving MEMS-based piezoelectric cantilevers

摘要

Thin film capacitors of the lead-free (K0.5NaO3)NbO3 (KNN) with (100) orientation were grown on Pt/Ti/SiO2/SOI (silicon-on-insulator) substrates by pulsed laser deposition. The films are pure phases and do not show other crystal orientations. The remnant polarization P-r, saturation polarization P-sat, longitudinal d(33,f) and transverse (d(31,f) and e(31,f)) piezoelectric coefficients of the KNN films were determined (P-r= 12.6 mu C/cm(2), P-sat=25.0 mu C/cm(2), d(33,f)=58 pm/V, d(31,f)= -42 pm/V and e(31,f) = -5.6 C/m(2)). These values are well comparable with the highest values reported for lead-free films of different compositions and therefore these KNN films form a potential alternative to PZT films in lead-free MEMS applications. (C) 2015 Elsevier B.V. All rights reserved.