Hello Spinlanders,
We’re trying to collect 13C MAS NMR of a reduced graphene oxide, which is expected to have some conductivity. I haven’t worked with semi-conductive samples before.
We tried 13C MAS with low power (20 kHz) 1H decoupling. We had to stop immediately, as we observed FID spikes characteristic of arcing.
We then tried 13C MAS with no decoupling, which produced a broad 13C resonance. Even though there were no spikes in the FID, we stopped after 12 scans out of an abundance of caution.
Does anyone know of a reliable metric to test whether a sample is ‘safe’ for the probe, and can ‘unsafe’ samples be fixed by mixing them with an inert powder?
I’d be grateful to hear any experiences with NMR of semi-conductive/conductive samples that you’d like to share – I really know nothing about the topic!
--- Our Setup ---
Bruker 500 MHz WB spectrometer
4 mm MAS probe _at_ 12.5 kHz
13C pulse _at_ 38 kHz (6.65 us)
1H decoupling _at_ 20 kHz (but we would like to go higher!)
D1 = 40 s or 20 s.
Many thanks,
Sameer
--
Sameer Al-Abdul-Wahid, Ph.D.
Manager, Nuclear Magnetic Resonance Centre
University of Guelph
50 Stone Road East, Guelph, ON N1G 2W1, Canada
Tel: 519-824-4120 x58914
Web: http://nmr.uoguelph.ca/
Received on Tue Sep 11 2018 - 03:02:24 MST