No-heating deposition of ferroelectric x%YO${}_{1.5}$-(100-x%)(Hf${}_{1-y}$Zr${}_y$)O${}_2$ films

The no-heating deposition of x%YO${}_{1.5}$-(100-x%)(Hf${}_{1-y}$Zr${}_y$)O${}_2$ (x = 0 - 0.09, y = 0, 0.25, 0.50, and 1) is achieved using a radio-frequency magnetron sputtering method. To investigate the crystal structure and ferroelectric properties, epitaxial films are grown on (111)-oriented indium tin oxide (ITO)/(111) Y-stabilized zirconia (YSZ) substrates. The ferroelectric orthorhombic phase is obtained for the 5-7%YO${}_{1.5}$-95-93%HfO${}_2$ and 5%YO${}_{1.5}$-95% (Hf${}_{0.75}$Zr${}_{0.25}$)O${}_2$ films. The field-induced phase transition from tetragonal to orthorhombic is confirmed for the 8%YO${}_{1.5}$-92%HfO${}_2$ and 5%YO${}_{1.5}$-95%(Hf${}_{0.50}$Zr${}_{0.50}$)O${}_2$ films. The remnant polarization (P${}_r$) and coercive field (E${}_c$) are 12-19 µC cm${}^{-2}$ and 2,000-2,500 kV cm${}^{-1}$, respectively. The piezoelectric response of 1 µm thick films is investigated for 6%YO${}_{1.5}$-94% HfO${}_2$, 7%YO${}_{1.5}$-93%HfO${}_2$, and 5%YO${}_{1.5}$-95%(Hf${}_{0.50}$Zr${}_{0.50}$)O${}_2$ films, which have piezoelectric coefficients (d${}_{33}$) of 1.0, 3.3, and 5.0 pm V${}^{-1}$, respectively. These results show no-heating deposition of x%YO${}_{1.5}$-(100-x%)(Hf${}_{1-y}$Zr${}_y$)O${}_2$ films with ferroelectric and piezoelectric properties. (© 2023 The Authors. physica status solidi (a) applications and materials science published by Wiley‐VCH GmbH)