Control of strain in thin diamond nitrogen-vacancy layers for magnetometry applications
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2023-03-08 |
| Authors | Teodoro Graziosi, Adam Rathmill, R. L. Patel, Nicola Palmer, Andrew M. Edmonds |
| Institutions | Element Six (United Kingdom) |
Abstract
Section titled āAbstractāNV-based magnetometry in single-crystal diamond grown by chemical vapour deposition (CVD), is now a wellestablished technology with demonstrated applications in DC and AC bulk magnetometry. The approx. 500 Āµm thick plates normally used offer limited contrast when attempting to measure the magnetic properties of small samples (for example biological samples or minerals) placed in proximity of the diamond magnetic sensor. Such applications would benefit from a few Āµm high-[NV] layer on a low luminescence substrate in order to collect the signal only from NV centres spatially close to the area of interest, allowing the formation of a magnetic image with increased resolution. It is important to ensure that the strain in the high-[NV] layer is spatially uniform and low in magnitude, to preserve the magnetic resolution and to avoid unusable regions on the magnetic sensor. Established techniques to manage strain during CVD diamond growth are not applicable for the deposition of a few Āµm of material; normally, the substrate would undergo extensive plasma etching to remove contaminants and polishing damage from the surface of the substrate. This is not possible for thin layers, since the etching would increase the roughness and produce NV layers with non-uniform thickness. Here, we present recent developments to obtain thin, high-[NV] layers on high purity substrates with large areas of low strain, by discussing the substrate preparation and strain characterisation before and after growth.