Doping of diamond by the in-diffusion of Li in natural type Ia and IIa single crystal diamond plates was investigated. The lithium incorporation was achieved by direct in-diffusion from a Li2O source 400 and 650C. Using

secondary ion mass spectroscopy, depth profiling, concentrations of Li of up to 8.0 x 1021/cm3, and gradually decreasing to 1.0 x 1019/cm3 at 0.5μm below the surface, were measured. From these profiles, the diffusion of lithium was found to be given by:

D(cm2/s) = 2 x 10-10 exp[-0.9(eV)/kT]

J.Te Nijenhuis, G.Z.Cao, P.C.H.J.Smits, W.J.P.Van Enckevort, L.J.Giling, P.F.A.Alkemade, M.Nesládek, Z.Remeš: Diamond and Related Materials, 1997,  6[11], 1726-32