Solution-Based Fabrication of High-Performance K$_{0.5}$Na$_{0.5}$NbO$_3$ Thin Films for Surface Haptics

Nagamalleswara Rao Alluri; Longfei Song; Stephanie Girod; Barnik Mandal; Juliette Cardoletti; Vid Bobnar; Torsten Granzow; Veronika Kovacova; Adrian-Marie Philippe; Emmanuel Defay; Sebastjan Glinsek

arXiv · 2502.21066

Solution-Based Fabrication of High-Performance K$_{0.5}$Na$_{0.5}$NbO$_3$ Thin Films for Surface Haptics

Nagamalleswara Rao Alluri·Longfei Song·Stephanie Girod·Barnik Mandal·Juliette Cardoletti·Vid Bobnar·Torsten Granzow·Veronika Kovacova·Adrian-Marie Philippe·Emmanuel Defay·Sebastjan Glinsek

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Abstract

K$_{0.5}$Na$_{0.5}$NbO$_3$ is among the most promising lead-free piezoelectrics. While its sputtered films match the performance of the champion piezoelectric Pb(Zr,Ti)O$_3$, reproducible processing of high-quality and time-stable solution-processed K$_{0.5}$Na$_{0.5}$NbO$_3$ films remains challenging. Here, we report 1 $\mu$m-thick Mn-doped K$_{0.5}$Na$_{0.5}$NbO$_3$ films prepared through a chemical solution deposition process, which have perfectly dense microstructure and uniform composition across their thickness. The films exhibit a high transverse piezoelectric coefficient ($e_{31,f} = -15.4$ C/m$^2$), high dielectric permittivity ($\varepsilon_r \approx 920$), low dielectric losses ($\tan\delta = 0.05$) and can withstand electric fields up to at least 1 MV/cm. The functional properties show excellent stability over time, and the synthesis process is reproducible. Furthermore, a surface acoustic haptic device is demonstrated by using K$_{0.5}$Na$_{0.5}$NbO$_3$ thin-film actuators. The results demonstrate the high potential of Mn-doped K$_{0.5}$Na$_{0.5}$NbO$_3$ films to become a replacement for lead-based Pb(Zr,Ti)O$_3$ films in piezoelectric applications.

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Nagamalleswara Rao Alluri, Longfei Song, Stephanie Girod, Barnik Mandal, Juliette Cardoletti, Vid Bobnar, Torsten Granzow, Veronika Kovacova, Adrian-Marie Philippe, Emmanuel Defay, Sebastjan Glinsek. 2025-02-28. Solution-Based Fabrication of High-Performance K$_{0.5}$Na$_{0.5}$NbO$_3$ Thin Films for Surface Haptics. https://arxiv.org/abs/2502.21066

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