Synthesis, Experiments and Theory of Relaxor Ferroelectrics
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: Synthesis, Experiments and Theory of Relaxor Ferroelectrics in High Electric Fields for Energy Storage We propose a joint research program using the expertise and facilities at three University of California campuses (Berkeley, Davis, Riverside) and at Los Alamos National Laboratory (LANL) towards the important goal of developing materials and interfaces for high density energy storage using electric fields. There is a compelling national need for such work as noted in the DOE Basic Energy Sciences 2 April 2007 report “Basic Research Needs For Electrical Energy Storage”, where they write: "Revolutionary breakthroughs in EES have been singled out as perhaps the most crucial need for this nation’s secure energy future". High electric fields, highly polarizable matter, and nano length scales interact non-linearly to modify the density of electronic and vibrational states and the fundamental thermo-dynamics at interfaces. We have isolated two specific important problems to study that take advantage of ongoing and planned experimental and modeling activity at LANL. These are studies of so-called “Relaxor Ferroelectrics” when prepared with deliberate nanoscale structure, and their chemical and electronic interactions with nanostructured metal electrodes, specifically carbon nanotubes and various nanowires. LANL has or is now developing unique capabilities to fabricate and measure both individual nanocapacitor structures from these materials and ensemble arrays of ‘nanowire’ capacitor structures. The relaxor ferroelectrics are unique in their extremely high dielectric constants and exhibit significant shifts in electron and phonon density of states at high electric fields, unlike conventional dielectric materials. Relaxors with very small (nanometer) domain sizes are ripe for studies of intrinsic properties and possibly enormous and as-yet untested effects of similarly nanometer sized metal electrodes. There is tremendous potential for new properties (electrical, thermodynamic, and electro-caloric) to emerge when this highly polarizable material is fabricated with nanoscale dimensions and placed near a curved conducting nanoelectrode. The potential is there for next generation solid state capacitors and solid electrolytes, leading to large increases in reversible electrical energy storage. We will focus on both non-stoichiometric perovskite-based relaxor ferroelectrics, some of the most polarizable materials known, and on polymer-based ferroelectrics. The unique nanocalorimetry developed by UC Berkeley and the exquisitely sensitive thermochemistry for which Navrotsky at Davis is renowned will be used to extract important thermodynamic properties from nanocomposites and ensembles of functionalized nano electrodes coated with electrolytes or dielectrics. The experimental effort will be closely aligned with theoretical insights on modeling internal electric fields and associated ferro-elastic changes at the nano-scale in random media and the non-linear solution of the resulting model to be carried out at UC Riverside. The work at the University of California will inform the ongoing state-of-the-art molecular dynamics and chemistry models, measurements, and nanostructures developed at Los Alamos National Laboratory under the LANL Electrical Energy Storage Program initiatives.