A study of piezoelectric orthorhombic Ta₂O₅

In 1985 it was first reported that monoclinic Ta₂O₅ has piezoelectric properties comparable to ZnO. In this work we report on the deposition, characterization, and qualitative assessment of the piezoelectric behavior of orthorhombic Ta₂O₅. Reactive magnetron sputtering was used to deposit thin films of Ta₂O₅ onto substrates of 316L stainless steel. Without substrate heating the crystallinity was poor. A rapid thermal anneal improved the crystallinity. The orthorhombic phase was dominantly present on all substrates. The piezoelectric property was qualitatively assessed, including a high temperature test at 650°C.