Nonlinear optical imaging of coupled breakdown dynamics in dielectrics and ferroelectrics
Abstract
A primary focus of this research proposal is on the nonlinear optical characterization of materialsgermane to the breakdown, or other failure, modes associated with thermal degradation,electromechanical processes in prototypical dielectrics and new developed ferroelectrics. Forthese studies, we plan to develop more advanced nonlinear optical techniques including SHGmicroscopy and time-resolved two color pump-probe spectroscopy to image and understand insitucoupled breakdown processes around interfaces and bulk boundaries that are difficult toobtain through other methods. Both techniques will be adapted to dielectric and ferroelectricsamples, including BaTiO3, SrTiO3, and their bicrystals to study ionic defect electromigration,space charge accumulation, ionic degradation, and electrical and thermal breakdown near grainboundaries and interfaces.Specifically, SHG microscopy will be utilized to image crystallographic texturing andferroelectric domain structures to reveal stress-induced microstructural inhomogeneities. We willmeasure the real-time SHG responses as a function of applied electrical bias and as a function oftemperature to reveal the modified electronic structures related to oxygen vacancy states withchanging stoichiometry, doping and local microstructures. Bulk characterization of defects anddistribution of strain fields due to oxygen vacancy migration will be performed by time-resolvedtwo color pump-probe spectroscopy. In addition, due to the still burgeoning interest in highenergy storage applications of ferroelectric thin film materials, we propose a systematic study onfundamental aspects of structural phase and domain properties in Ba(Zr,Ti)O3 ferroelectricfilms. We will use both nonlinear optical techniques to investigate phase segregation, the detailsof mixed domains and phases will help to understand the mechanism of high performance energystorage.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 11, 2017
- Source ID
- FA95501710339
Entities
People
- Steven Greenbaum
Organizations
- Air Force Office of Scientific Research
- Research Foundation of The City University of New York
- United States Air Force