Chemical sensor based on nitrogen-vacancy centers in diamond
Loading...
Date
2020
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
During the last decade, the nitrogen-vancancy (NV) center in diamond has emerged as a solid platform for nanoscale quantum sensing, within which is electrometry and magnetometry. Owing to the NV center high sensitivity and the fact that the diamond withstands adverse environmental conditions, a chemical sensor based on NV centers is a promising candidate for measurements during mining processes. Here, we use a microfluidic confocal microscope and a shallow-implanted diamond with different implantation spots, which are circular areas of 35 um diameter, to perform longitudinal spin relaxometry in the presence of sodium sulfate in aqueous solution in order to determine the T1 relaxation time behaviour. We observed that by increasing sodium sulfate concentration, the longitudinal spin relaxation time decreases, being this effect more noticeable as the NV centers are closer to the diamond surface and, with respect to the 1/T1 parameter, it gives signs to exhibit a quadratic response with concentration. On the other hand, the T1 values are distributed along the implantation spot diameter, reaching minimum values around the spot center and maximum values at the edges, which is evidence that NV centers with different orientations coexist in the same implantation spot. These results lay the foundation for a possible second stage in our chemical sensor development in which, after certain set-up modifications, new pulse-sequence protocols could be tried.
Description
Tesis (Master in Physics)--Pontificia Universidad Católica de Chile, 2020