Investigation of Piezoelectricity and Curie Temperature of Pb(Mg1/3, Nb2/3)O3-PbTiO3 Epitaxial Thin Film on Si Prepared by Sputter Deposition With Fast Cooling.

Abstract

This paper reports on an abnormally high Curie temperature ( $T_{c}$ ) of a Pb(Mg1/3, Nb2/3)O3-PbTiO3 (PMN-PT) epitaxial thin film on Si prepared by sputter deposition with fast cooling. This deposition method was previously applied to Pb(Mn, Nb)O3-Pb(Zr, Ti)O3, and a c-axis-oriented epitaxial film with high $T_{c}$ was obtained. Using the same method, a crack-free 2- $\mu \text{m}$ -thick PMN-PT thin film was epitaxially grown on a Si substrate covered with buffer layers. The piezoelectricity, $\vert \text{e}_{31,f}\vert $ , was as large as 18~19 C/m2 under an electric field ranging from 25 to 75 kV/cm. The temperature characteristics of the dielectric constant and crystalline structure were significantly different from those of a bulk single crystal of PMN-PT, and suggested $T_{c}$ higher than 500 °C. The enhanced $T_{c}$ was possibly caused by thermally induced compressive strain received from the Si substrate. This approach can be an effective method for breaking the well-known tradeoff relationship between piezoelectricity and $T_{c}$ of a piezoelectric thin film. 0.