Experimental Validation of Multiscale Modeling Approach to Materials Discovery for Radiation Detection Materials
EMSL Project ID
25682
Abstract
In the field of crystal growth modeling, it is not currently possible to specify the atomistic accuracy at the continuum scale in a rigorous manner [1]. Continuum scale models of growth are robust, some with parameterized defect production rates during growth, and can be used to optimize growth conditions for desired growth processes. At the atomic scale, computational tools exist to study individual point defect interactions [2], surface growth processes and kinetics [3], and electronic material properties, as examples. However, there is no established mathematical method to link the two modeling approaches, although many are trying to do so. The main benefits of development of such a link are 1) the ability to accurately predict growth defects, defect structures, and defect production rates on a microscopic scale, 2) transfer those data to a on the fly model on macroscopic scale, and 3) make improved growth predictions. Literature data indicate that it is the microscopic defects that determine overall crystal properties in terms of radiation detection [4]. Under an NA-22 funded project led by Chuck Henager, a new multiscale approach to crystal growth is being developed at PNNL to construct a robust and predictive materials discovery and processing tool. This new model and tool will help to identify crystal structure families and compounds. The material which can be successfully processed into high-quality single crystals for room temperature, high-resolution gamma detectors is most likely to contain within these families. Under this project, we will develop and deliver a new modeling approach, and thus a new tool in the form of a working model. This tool will allow more fidelity in modeling crystal growth processes than currently exists to predict growth rates, growth mechanisms, defect and impurity incorporation rates, and material properties.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2007-05-31
End Date
2008-09-07
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Accepted for publication in Journal of Crystal Growth, 2008.
Annual Project Review presentation, August 15, 2008, Richland, WA
Gao F, HY Xiao, XT Zu, M Posselt, and WJ Weber. 2009. "Defect-Enhanced Charge Transfer by Ion-Solid Interactions in SiC using Large-Scale Ab Initio Molecular Dynamics Simulations." Physical Review Letters 103(2):Article number: 027405. doi:10.1103/PhysRevLett.103.027405
Gao F, WJ Weber, HY Xiao, and XT Zu. 2009. "Formation and properties of defects and small vacancy clusters in SiC: Ab initio calculations ." Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms 267(18):2995-2998. doi:10.1016/j.nimb.2009.06.018
Henager CH, Jr, DJ Edwards, AL Schemer-Kohrn, M Bliss, and JE Jaffe. 2009. "Preferential orientation of Te precipitates in melt-grown CZT." Journal of Crystal Growth 311(9):2641–2647. doi:10.1016/j.jcrysgro.2009.03.002
Sundaram SK, CH Henager, DJ Edwards, AL Schemer-Kohrn, M Bliss, BJ Riley, MB Toloczko, and KG Lynn. 2011. "Hierarchical Microstructures in CZT." Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment 652(1):174-177. doi:10.1016/j.nima.2010.09.128
Sundaram SK, CH Henager, Jr, DJ Edwards, AL Schemer-Kohrn, M Bliss, and BJ Riley. 2011. "Electron Backscatter Diffraction Analysis of a CZT Growth Tip from a Vertical Gradient Freeze Furnace." Journal of Crystal Growth 329(1):12-19. doi:10.1016/j.jcrysgro.2011.02.008