Abstract
The temperature dependence of the magnetic-resonance spectra of nitrogen-vacancy () ensembles in the range of 280–330 K was studied. Four samples prepared under different conditions were analyzed with concentrations ranging from 10 ppb to 15 ppm. For all samples, the axial zero-field splitting (ZFS) parameter was found to vary significantly with temperature, , as . The transverse ZFS parameter was nonzero (between 4 and 11 MHz) in all samples, and exhibited a temperature dependence of . The results might be accounted for by considering local thermal expansion. The temperature dependence of the ZFS parameters presents a significant challenge for diamond magnetometers and may ultimately limit their bandwidth and sensitivity.
- Received 23 November 2009
DOI:https://doi.org/10.1103/PhysRevLett.104.070801
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