[10a-B31-1~12] 6.1 Ferroelectric thin films

11:00 AM - 11:15 AM JST(2:00 AM - 2:15 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation Award

[10a-B31-8] Investigation of Influence of Silicon Elastic Plate Thickness on Curie Temperature of Single-Crystal PZT Thin Film and Its Underlying Mechanism

〇(M2)Shunsaku Nachi¹, Shinya Yoshida¹, Akihiko Teshigahara¹ (1.Shibaura Univ.)

Keywords:

ferroelectric thin film,single-crystal pzt,curie temperature

The influence of silicon (Si) elastic plate thickness on the Curie temperature (Tc) of single-crystal PZT thin films was investigated to achieve high-heat-resistant PZT-MEMS. Circular diaphragm samples with various Si thicknesses as well as a free-standing membrane sample were fabricated, and their Tc values were evaluated from the temperature dependence of relative permittivity. Although Tc decreased as the Si plate was thinned, the enhancement of Tc was clearly maintained even at a thickness of 30 µm. Furthermore, the Si thickness dependencies of both the thermal stress estimated by Timoshenko's bimetal theory and the measured Tc exhibited a similar trend. This correlation successfully validated the hypothesis that thermal stress, arising from the difference in thermal expansion coefficients, is the primary factor driving the Tc enhancement.