The diffusivity of B in single crystals (75.9at%Ni) was measured at between 773 and 1345K by means of secondary ion mass spectrometry, using stable 10B and 11B isotopes. It was found that the data obeyed a perfect Arrhenius relationship of the form,

D (m2/s) = 1.53 x 10-4exp[-227.6(kJ/mol)/RT]

When compared with Ni self-diffusion in this material, which occurred via thermal vacancies, the B diffusion was found to be 1000 to 10000 times faster.

S.Frank, U.Sodervall, C.Herzig: Intermetallics, 1997, 5[3], 221-7