Tuning the Functionality of Materials with Reversible Phase Transitions
Abstract
We investigated solid-state phase transitions of complex metal oxides as an effective way to dynamically control macroscopic material properties and their functionality via lattice and defect engineering. We demonstrated that careful film growth and the strain generated by buffer layers can provide an effective way for tuning the transition temperature of metal oxides with reversible phase transitions such as VO2 films and in the process control their functionality. We also demonstrated an ultrafast switching capability (<400 fs) of the strained VO2 films using a time-resolved optoelectronic autocorrelation measurement technique, indicating that it is possible to selectively activate the metallic phase without inducing the associated structural transition. Furthermore, to demonstrate the applicability of this basic research, we fabricated VO2-based, layered solid-state radiators for spacecraft thermal control. The multilayer radiators in this work are well suited for spacecraft thermal control because they are passive and self-regulating. We also demonstrated that perovskite conducting oxides can provide a large tunable permittivity in the mid-wave IR (MWIR) range (2-7 m) for MWIR plasmonic devices. These results are highly relevant to various Navy and DoD applications ranging from optical communications to low observables. Lastly, we were able to synthesize two different structural phases of epitaxial Ti2O3 films. The films grown at 485 deg C are a corundum structure with p-type carriers while the films grown at 730 deg C become an orthorhombic structure with n-type carriers. These results can open up the possibility of p-n homojunctions that will strongly impact future Navy and DoD applications including IR detection and thermal energy conversion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 26, 2023
- Accession Number
- AD1191928
Entities
People
- Alberto Piqué
- Heungsoo Kim
- Raymond C. Auyeung
Organizations
- United States Naval Research Laboratory