Synthesis of Defect-Mitigating Tunable Dielectric Materials with Atomic-Layer Control
Technical Report,15 Aug 2012,14 Aug 2015
Cornell University Ithaca United States
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The miniaturization and integration of frequency-agile microwave circuitselectronically tunable filters, resonators, phase shifters andmorewith microelectronics offers tantalizing device possibilities, yet requires thin films whose dielectric constant at GHz frequencies canbe tuned by applying a quasi-static electric field. We have achieved a new type of tunable microwave dielectric with a figure of merit atroom temperature that rivals all known tunable microwave dielectrics. This was achieved in biaxially strained Srn1TinO3n1 phases withn 3 at frequencies up to 125 GHz. We have also understood the growth mechanism of these new materials. For the precise growth ofSrn1TinO3n1 RuddlesdenPopper RP phases, stoichiometric deposition leads to the loss of the first RP rock-salt double layer, butgrowing with a strontium-rich surface layer restores the bulk stoichiometry and ordering of the subsurface RP structure. Our resultsdramatically expand the materials that can be prepared in epitaxial heterostructures with precise interface controlfrom just the n endmembers perovskites to the entire RP homologous seriesenabling the exploration of novel quantum phenomena at a richer variety ofoxide interfaces.
- Electricity and Magnetism
- Miscellaneous Materials