Dependence of e31,f on polar axis texture for tetragonal Pb(Zrx,Ti1−x)O3 thin films

• Published in: Journal of applied physics 2014-09, Vol.116 (10)
• Main Authors: Yeager, Charles B, Ehara Yoshitaka, Oshima Naoya, Funakubo Hiroshi, Trolier-McKinstry, Susan
• Format: Article
• Language: English
• Subjects: Applied physics; Composition; Dependence; Energy harvesting; Figure of merit; Lead zirconate titanates; Piezoelectricity; Silicon substrates; Strontium titanates; Texture; Thin films; Zirconium
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4895339

It was shown by Ouyang et al. [Appl. Phys. Lett. 86, 152901 (2005)] that the piezoelectric e31,f coefficient is largest parallel to the spontaneous polarization in tetragonal PbZrxTi1−xO3 (PZT) films. However, the expected piezoelectric data are typically calculated from phenomenological constants derived from data on ceramic PZT. In this work, the dependence of e31,f on c-axis texture fraction, f001, for {001}PZT thin films was measured by growing films with systematically changed f001 using CaF2, MgO, SrTiO3, and Si substrates. An approximately linear increase in e31,f with f001 was observed for compositions up to 43 mol. % Zr, and 100% c-domain properties were extrapolated. It was demonstrated that c-axis PZT films can achieve e31,f exceeding −12 C/m2 for many tetragonal compositions. The energy harvesting figure of merit, e31,f2/εr, for c-axis PZT films surpassed 0.8 C2/m4. This is larger than the figure of merit of gradient-free PZT films grown on Si substrates by a factor of four.