High-tunability, low-loss multiferroics based on domain-wall resonance
Abstract
This project explores and develops the fundamental understanding of domain-wall (DW) oscillation and resonance effects in thin-film solid-solution multiferroic materials. Leveraging advanced materials synthesis, first-principles calculations and phase-field/Monte Carlo simulations, and cutting-edge characterization, the program will address limitations in the design and realization of highly tunable and low-loss dielectrics which are key for a variety of communications technologies. The goal will be to develop the know-how and approaches to achieve the desired combination of high quality factor (Q) and high tunability by rethinking the role of domain walls in materials. By investigating so-called novel manifold domain wall (DW)-variant material films wherein high DW density frustrates the evolution of conventional long-range ferroelectric ordering, it should be possible to realize room-temperature dielectric losses which are low, and comparable to the best single-crystal materials, and Q values considerably larger than the zero-field intrinsic limit for the material. This would overcome long-standing challenges in achieving high-Q resonance with high tunability of resonant frequency. In essence, the program will redefine the role of domain walls and DW oscillations, which are usually viewed as sources of loss, thereby revealing a pathway for novel performance. As such, the specific objects of the program include: ¥ Fundamental study of domain structures in designer materials Ð Study how composition, strain state, and temperature affect the domain-wall energetics and structure that then will play a crucial role in DW dynamics and resonance effects. Because of the chemical complexity and interplay between electric and magnetic degrees of freedom, such environment-structure-property relationships cannot be simply extrapolated from known effects. Thus, both theoretical modeling and experimental efforts will obtain microscopic insights into domain structure and energetics. ¥ Probing domain-wall dynamics (dielectric losses and domain-wall resonances) Ð Study the dielectric and magnetic response arising from the dynamics of domain walls for polydomain configurations identified as the most promising candidates for low loss. An integrated theoretical modeling and experimental effort will probe the frequency-dependent dielectric and magnetic response under a variety of applied biases, environmental conditions, and electrode configurations; including developing understanding of sub-ns timescale dynamics. In turn, the program will optimize the desired response characteristics (mostly loss) by changing these variables. Overall, the program will significantly advance the scientific state-of-the-art, including: 1) Overcoming intrinsic limitations in Q based on material resonance. 2) Addressing requirements for high tunability and high Q; something not typically found in a single material. 3) Identifying approaches to achieve high Q at high operating frequencies (well into the GHz regime). All told, the innovative aspects of the project involve the use of ferroelectric domain walls to enable thermally-activated, large GHz polarization fluctuations that will be exploited to create new materials that possess electromagnetic resonances, exceptionally low dielectric loss, and extraordinarily high tuning sensitivity and range. This requires advanced in the theory/modeling, and synthesis and characterization of complex materials; advances widely applicable beyond this program. In turn, these outcomes address some of the most compelling unsolved science and technology challenges for Army defense communications, including positioning, navigation, and timing (PNT) capabilities by developing new materials that can deliver disruptive advances in frequency synthesis and selectivity, spectrum management, and reduced power requirements.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 25, 2021
- Source ID
- W911NF2110126
Entities
People
- Jonathan E Spanier
Organizations
- Army Contracting Command
- Drexel University
- United States Army