Serial sectioning methods were used to study the diffusion of P in single crystals, of 4N-purity material, at 1880 to 2180K. The results could be described by:

D (cm2/s) = 2.68 x 101 exp[-121.8(kcal/mol)/RT]

V.P.Iovkov, A.S.Panov, A.V.Ryabenko: Izvestiya Akademii Nauk SSSR, 1978, 1, 78-9