Quantitative Phase Mapping of the Negative Capacitance State in a Ferroelectric Heterostructure
Abstract
Negative capacitance is a new state within ferroelectric materials that exploits a region of thermodynamic space that is otherwise forbidden. Stabilization in this forbidden state is accomplished by placing the ferroelectric material in a situation where an electrostatic frustration ensues due to surrounding dielectrics in a way that suppresses polarization in the ferroelectric material. This can greatly increase the overall permittivity of the material, beyond the limits possible by conventional dielectric engineering. Such enhanced permittivity has many potential applications spanning a broad area from energy efficient computing to energy storage. In crystalline heterostructures such as epitaxially grown superlattices, material optimization followed by a High-Resolution Transmission Electron Microscopy and X-Ray Diffraction can be used to pin-point the volume fractions of different phases that lead to the largest negative capacitance effect. However, in poly-crystalline or amorphous-like materials, such techniques can only provide only a qualitative estimate. On the other hand, poly-crystalline ferroelectric heterostructure constitute an intriguing material system as many well-established concepts of ferroelectricity, developed over decades for crystalline ferroelectric materials, do not apply to them.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 06, 2025
- Source ID
- FA95502510013
Entities
People
- Sayeef Salahuddin
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of California Regents