This paper reports on an abnormally high Curie temperature (Tc) 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 Tc was obtained. Using the same method, a crack-free 2- μ m -thick PMN-PT thin film was epitaxially grown on a Si substrate covered with buffer layers. The piezoelectricity, |e31,f|, was as large as 1819 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 Tc higher than 500 °C. The enhanced Tc 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 Tc of a piezoelectric thin film.
|ジャーナル||IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control|
|出版ステータス||Published - 2018 9|
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