Microwave field mapping for EPR-on-a-chip experiments.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39151005.
- Also identified by DOI 10.1126/sciadv.ado5467 and PMC identifier 11801239.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Electron paramagnetic resonance-on-a-chip (EPRoC) devices use small voltage-controlled oscillators (VCOs) for both the excitation and detection of the EPR signal, allowing access to unique sample environments by lifting the restrictions imposed by resonator-based EPR techniques. EPRoC devices have been successfully used at multiple frequencies (7 to 360 gigahertz) and have demonstrated their utility in producing high-resolution spectra in a variety of spin centers. To enable quantitative measurements using EPRoC devices, the spatial distribution of the <i>B</i><sub>1</sub> field produced by the VCOs must be known. As an example, the field distribution of a 12-coil VCO array EPRoC operating at 14 gigahertz is described in this study. The frequency modulation-recorded EPR spectra of a "point"-like and a thin-film sample were investigated while varying the position of both samples in three directions. The results were compared to COMSOL simulations of the <i>B</i><sub>1</sub>-field intensity. The EPRoC array sensitive volume was determined to be ~19 nanoliters. Implications for possible EPR applications are discussed.