
NSF Org: |
EAR Division Of Earth Sciences |
Recipient: |
|
Initial Amendment Date: | November 12, 2019 |
Latest Amendment Date: | November 12, 2019 |
Award Number: | 2001444 |
Award Instrument: | Standard Grant |
Program Manager: |
Jennifer Wade
jwade@nsf.gov (703)292-4739 EAR Division Of Earth Sciences GEO Directorate for Geosciences |
Start Date: | December 1, 2019 |
End Date: | November 30, 2021 (Estimated) |
Total Intended Award Amount: | $22,189.00 |
Total Awarded Amount to Date: | $22,189.00 |
Funds Obligated to Date: |
|
History of Investigator: |
|
Recipient Sponsored Research Office: |
110 8TH ST TROY NY US 12180-3590 (518)276-6000 |
Sponsor Congressional District: |
|
Primary Place of Performance: |
NY US 12180-3590 |
Primary Place of
Performance Congressional District: |
|
Unique Entity Identifier (UEI): |
|
Parent UEI: |
|
NSF Program(s): | Petrology and Geochemistry |
Primary Program Source: |
|
Program Reference Code(s): |
|
Program Element Code(s): |
|
Award Agency Code: | 4900 |
Fund Agency Code: | 4900 |
Assistance Listing Number(s): | 47.050 |
ABSTRACT
Our knowledge of the Earth and its history strongly depends on our understanding of the materials that make up the bulk of the planet. Laboratory measurements of Earth materials (e.g., rocks, minerals, and magmas) are used in conjuction with direct observations of the planet and numerical models to help build the rich and complex view of the Earth and its inner workings that we have today. In this project, the investigators seek to further our understanding of the atomic-scale physical properties of several relevant Earth materials through the development of a very high resolution materials characterization technique called positron annihilation spectroscopy. The benefit of this technique is that it allows for direct investigation of crystalline solids at an atomic level, which is not routinely done with other conventional methods used in the geosciences. This project aims to build a new positron annihilation lifetime spectroscopy apparatus, test and calibrate the instrument, and characterize the atomic scale defect populations in several important Earth materials including metals, oxides, and silicate minerals. The undertaking will involve interdisciplinary collaborations between nuclear physicists and experts in the area of materials characterization and geoscience. The project will also support two female faculty, undergraduate curriculum development, and advanced student research at a liberal arts college.
Understanding defects in crystalline solids is important for our general understanding of Earth materials because of their relationship to atomic mobility (diffusion) within crystals, nucleation of crystals and formation of new phases as well as electrical and heat transfer properties. When a significant population of defects are included in the crystal structure, it may affect transport properties of the crystal significantly. Many crystals in natural systems may have been exposed to defect creating events including radiation damage and deformation. To accurately apply experimentally determined diffusion parameters to natural systems, a thorough understanding of the relationship between defects and diffusion is crucial. Direct measurements of defect populations in natural and synthetic Earth materials is generally lacking. Positron annihilation spectroscopy is a non-destructive technique used to characterize defects and voids in materials at a sub nm to atomic scale. The technique has been used extensively in the materials science and nuclear materials communities for decades to examine defect properties and the effects of radiation damage on synthetic and industrial materials, but has not yet gained popularity in the Earth sciences community. The goal of this project is to develop a methodology that will enable further investigation into the relationship between diffusion and defect populations by direct measurement of defects in a variety of Earth relevant materials using positron annihilation spectroscopy. The project will also contribute to the education and research training of undergraduate students and provide opportunities for interdisciplinary work between mineral physics, nuclear physics, materials science, and geochemistry.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
Our knowledge of the Earth and its history strongly depends on our understanding of the materials that make up the bulk of the planet. Laboratory measurements of Earth materials (e.g., rocks, minerals, and magmas) are used in conjunction with direct observations of the planet and numerical models to help build the rich and complex view of the Earth and its inner workings that we have today. Here, we have developed a positron-annihilation lifetime spectroscopy system that is designed to measure atomic scale defects within the crystal structures of common materials relevant to Earth science. Positron annihilation spectroscopy is a non-destructive technique used to characterize defects and voids in materials at sub-nanometer to atomic scales. The technique has been used extensively in the materials science and nuclear materials communities for decades to examine defect properties of materials and the effects of radiation damage on various synthetic and industrial materials, but has not yet gained popularity in the Earth science community. Many crystals in natural systems may have also experienced events that create defects, which include radiation damage and deformation. Our main focus for this initial project has been to build, test, and calibrate the instrument to prepare for more routine use of the technique with more complex Earth materials in the future. So far, we have completed extensive testing on pure MgO and pure Fe, and have shown that our set-up reproduces average lifetime values that fall within experimental uncertainty of those found in the peer reviewed literature for these and similar materials. We have also begun preliminary investigations of these materials after the crystal structure has been damaged through bombardment with an argon ion beam. A potential benefit of this technique is its relatively low cost to set up (<$60K) and relatively simple procedures for sample preparation. Furthermore, while the instrumentation does require that radiation safety protocols are established and followed, it doesn’t require any other specialized laboratory space or utilities such as high voltage power, chillers etc. This allows for the set-up to be more accessible to faculty and students at smaller institutions where support for extensive instrumentation may not be widely available. This project has involved interdisciplinary collaborations between nuclear physicists and experts in the area of materials characterization and geoscience, has provided support to the work of two female researchers, and has also made a significant contribution to the education and training of undergraduate students.
Last Modified: 02/23/2022
Modified by: Daniele J Cherniak
Please report errors in award information by writing to: awardsearch@nsf.gov.