Single Crystal Relaxor Ferroelectrics by Seeded Polycrystal Conversion
Abstract
The group at Lehigh University has implemented the successful application of Seeded Polycrystal Conversion (SPC) to ferroelectric materials. Initial work at Lehigh established the feasibility of using the SPC process to grow single crystals of the relaxor-based ferroelectric PbMg(1 /3)Nb(2/3))O(3-) 5mol%PbTiO3 (PMN-3 5PT) from seed crystals of the same composition. However, much work was needed to refine this process. Maintaining single crystal growth until full conversion of the polycrystal can only be achieved with a fundamental understanding of the factors that influence the migrating boundary. The present work addressed, in particular, the roles of liquid phase content and chemistry, matrix grain size, and porosity, as previous results have indicated these to be key variables. Some strides have been made in understanding the roles of each of the above key variables. In fact, over the past year, the Lehigh group has begun to model the effect of matrix grain size on single crystal growth. By improving this model, a better understanding of why single crystal growth slows can be achieved by pinpointing the mechanism of growth. Additionally, great progress has been made in microscopic characterization of samples as Lehigh has acquired a dual-beam focused ion beam (FIB). This instrument allows for the TEM preparation of samples across specific boundary interfaces in the PMN- PT system, previously unattainable with traditional sample preparation techniques. This will help gain a better understanding of the liquid phase chemistry and its role in the SPC process.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 08, 2003
- Accession Number
- ADA418287
Entities
People
- Derrick J. Rockosi
- Edward P. Gorzkowski
- Helen M. Chan
- Martin P Harmer
- Patrick T. King
Organizations
- Lehigh University