Surface acoustic wave propagation in PZT/YBCO/SrTiO3 and PbTiO3/YBCO/SrTiO3, epitaxial heterostructures

Epitaxial heterostructures of ferroelectric thin films (PZT, PbTiO3) on SrT iO3 substrate offer highly c-axis oriented films with promising piezoelectr ic properties. Theoretical analysis of SAW propagation characteristics with IDT electrodes on top of the piezoelectric films has been performed to obs erve the effect of an underlying epitaxially matched conducting oxide layer of YBCO on SrTiO3 substrate, The change in SAW propagation characteristics with a SrTiO3 over-layer on PZT/SrTiO3 structure has also been studied. Th e SrTiO3 over-layer shows enhanced values of electromechanical coupling coe fficient in the range of 3.65% to 12.72% for a SrTiO3 over-layer thickness varying from 0 to 0.12 lambda.