Nuclear spin-lattice relaxation of dilute spins in semiconducting diamond

Abstract

Absorption line shape and spin-lattice relaxation-time measurements have been made on ' C nuclei (1.1% abundant) in a type-IIb single-crystal semiconducting diamond. The line shape measurements are consistent with theoretical predictions for a dilute spin system. Over the temperature range 295-375 K, the spin-lattice relaxation time is long (3-4 h) and shows a temperature dependence which may be explained by means of a model in which spin diffusion plays a role, and the paramagnetic acceptor centers relax via an Orbach-type process involving excited states near the valence band.

Optically detected cross-relaxation spectroscopy of electron spins in diamond

“…The potential detection distance through cross-relaxation should be at least B8 nm, as estimated by the average separation of neighbouring NV À centres in our diamond sample, between which cross-relaxation is clearly detected in our measurements 39 (Supplementary Note 3). Such a detection distance would allow for observation and identification of dark electron spins deposited on the diamond surface 14 , if using shallow-implanted NV À centres in ultrapure diamond 3,40 .…”

Luminescent nanodiamonds for biomedical applications

“…The inherent difficulty with this technique is the low sensitivity of nuclear Reprinted by permission from Macmillan Publishers Ltd: Nature Nanotechnology (Chang et al 2008b(Chang et al ), copyright 2008 magnetism in combination with the low natural abundance of spin-active 13 C (1.1%) relative to 12 C. Methods to overcome this limitation include the production of nanodiamond grown from 13 C-rich sources and the use of nuclear hyperpolarisation (Hoch and Reynhardt 1988;Reynhardt and Terblanche 1997) which can dramatically increase the nuclear resonance signal.…”

Spin relaxation in disordered media

“…Important example of such systems is formed by nuclei 6 Li in the single crystal 7 Li 19 F. The system is accessible for direct experimental -NMR study due to unique coincidence of g-factors of stable nuclei 6 Li and -active nuclei 8 Li ( -nuclei) [4,5]. Therefore, we will consider below a model system (consisting of 6 Li nuclei in a LiF single crystal with addition of one -nucleus 8 Li) where nuclear polarization transfers from initially polarized 8 Li nucleus to the nearest nonpolarized 6 Li nuclei and then migrates over other 6 Li nuclei and might return back to the 8 Li.…”

“…Therefore, we will consider below a model system (consisting of 6 Li nuclei in a LiF single crystal with addition of one -nucleus 8 Li) where nuclear polarization transfers from initially polarized 8 Li nucleus to the nearest nonpolarized 6 Li nuclei and then migrates over other 6 Li nuclei and might return back to the 8 Li. Difference in speeds of processes in disordered subsystem 8 Li- 6 Li and matrix spins 7 Li 19 F produce a possibility to describe the polarization transfer within the subsystem by master equations [6] …”

“…Therefore, for the sake of brevity, we will discuss below homonuclear magnetically disordered systems mainly. Examples of corresponding experimental studies can be found in [7][8][9][10]. Observable values for these systems are free induction decay (FID) …”