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Matthew W. Dale

Publications and source records attributed to Matthew W. Dale.

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Medical applications of diamond magnetometry: commercial viability

The sensing of magnetic fields has important applications in medicine, particularly to the sensing of signals in the heart and brain. The fields associated with biomagnetism are exceptionally weak, being many orders of magnitude smaller than the Earth's magnetic field. To measure them requires that we use the most sensitive detection techniques, however, to be commercially viable this must be done at an affordable cost. The current state of the art uses costly SQUID magnetometers, although they will likely be superseded by less costly, but otherwise limited, alkali vapour magnetometers. Here, we discuss the application of diamond magnetometers to medical applications. Diamond magnetometers are robust, solid state devices that work in a broad range of environments, with the potential for sensitivity comparable to the leading technologies.

physics.app-ph

Electron paramagnetic resonance of the $\mathrm{N_{2}V^{-}}$ defect in $\mathrm{^{15}N}$-doped synthetic diamond

Nitrogen is the dominant impurity in the majority of natural and synthetic diamonds, and the family of nitrogen vacancy-type ($\mathrm{N_{n}V}$) defects are crucial in our understanding of defect dynamics in these diamonds. A significant gap is the lack of positive identification of $\mathrm{N_{2}V}^{-}$, the dominant charge state of $\mathrm{N_{2}V}$, in diamond that contains a significant concentration of electron donors. In this paper we employ isotopically-enriched diamond to identify the EPR spectrum associated with $^{15}\mathrm{N_{2}V}^{-}$ and use the derived spin Hamiltonian parameters to identify $^{14}\mathrm{N_{2}V}^{-}$ in a natural isotopic abundance sample. The electronic wavefunction of the $\mathrm{N_{2}V^{-}}$ ground state and previous lack of identification is discussed. The $\mathrm{N_{2}V}^{-}$ EPR spectrum intensity is shown to correlate with H2 optical absorption over an order of magnitude in concentration.

cond-mat.mtrl-sci