β-NMR
β-detected nuclear magnetic resonance (β-NMR) is a sensitive spectroscopic technique well-suited for interrogating matter at the microscopic level. It is quite akin to “conventional” magnetic resonance techniques (e.g., NMR, EPR, MRI, etc.), but uses the high-energy β-emissions from radioactive probe nuclei for signal detection. In this sense, it is quite similar to muon spin rotation, relaxation, and resonance (μSR), which shares the same detection scheme. While the requirement of a radioactive source limits implementations to specialized facilities (e.g., particle accelerators or nuclear reactors), the technique is uniquely able to probe material environments that are inaccessible through other means of study.
A modern implementation of the β-NMR technique can be found at TRIUMF’s Isotope Separator and Accelerator (ISAC) facility in Vancouver, BC, Canada.
An overview of the technique can be found in the recent review articles:
- Title
- Implanted-ion βNMR: a new probe for nanoscience
- Author
- W. A. MacFarlane
- Journal
- Solid State Nucl. Magn. Reson.
- Volume
- 68-69
- Pages
- 1-12
- Year
- 2015
- Abstract
-
NMR detected by radioactive beta decay, β-NMR, is undergoing a renaissance largely due to the availability of high intensity low energy beams of the most common probe ion, 8Li+, and dedicated facilities for materials research. The radioactive detection scheme, combined with the low energy ion beam, enable depth resolved NMR measurements in crystals, thin films and multilayers on depth scales of 2-200 nm. After a brief historical introduction, technical aspects of implanted-ion β-NMR are presented, followed by a review of recent applications to a wide range of solids.
- Graphic
-
- 10.1016/j.ssnmr.2015.02.004
- Title
- Status and progress of ion-implanted βNMR at TRIUMF
- Author
- W. A. MacFarlane
- Journal
- Z. Phys. Chem.
- Volume
- 236
- Issue
- 6-8
- Pages
- 757-798
- Year
- 2022
- Abstract
-
Beta-detected NMR is a type of nuclear magnetic resonance that uses the asymmetric property of radioactive beta decay to provide a "nuclear" detection scheme. It is vastly more sensitive than conventional NMR on a per nuclear spin basis but requires a suitable radioisotope. I briefly present the general aspects of the method and its implementation at TRIUMF, where ion implantation of the NMR radioisotope is used to study a variety of samples including crystalline solids and thin films, and more recently, soft matter and even room temperature ionic liquids. Finally, I review the progress of the TRIUMF βNMR program in the period 2015–2021.
- 10.1515/zpch-2021-3154
Additional (though somewhat dated) information can be found at: https://bnmr.triumf.ca.