An enabling material design to promote highly tunable, low loss, performance consistent BST thin films for tunable device applications

In this work we demonstrate that a compositionally stratified Ba1??xSrxTiO3 (BST) thin film design (BST60/40-BST75/25-BST90/10) combined with optimized metal-organic solution deposition (MOSD) film fabrication and post-deposition annealing process protocols results in low loss, highly tunable and temperature stable thin film heterostructures. The experimental data demonstrates that the compositionally stratified BST thin film heterostructure has a small-signal dielectric permittivity of 360 with a dissipation factor of 0.012 and a dielectric tunability of 65% at 444 kV/cm. These material properties exhibited minimal dispersion as a function of temperature ranging from 90 to ??10 ??C. Thus, our results suggest that this compositionally stratified material design is an excellent candidate for tunable devices which require both enhanced dielectric response and performance consistency in harsh operational temperature regimes.