The redistribution of Ni in a Ni/GaAs contact specimen was studied by using neutron activation and sectioning techniques at temperatures of between 360 and 870K. It was concluded that interdiffusion of the components took place in an elastic strain field which was generated by differences in the lattice parameters and thermal expansion coefficients of Ni, GaAs and intermetallic compounds which formed. At annealing temperatures below 570K, reactive diffusion of Ni took place, with an activation energy of 0.51eV. The formation of micro-cracks in the surface layers of the microcrystalline GaAs led to diffusion with an activation energy of 0.25eV. At annealing temperatures that were greater than 670K the internal electric field, and cluster formation, markedly affected the distribution of the components.

W.A.Uskov, A.B.Fedotov, E.A.Erofeeva, A.I.Rodionov, D.T.Dzhumakulov: Izvestiya Akademii Nauk SSSR - Neorganicheskie Materialy, 1987, 23[2], 186-9. (Inorganic Materials, 1987, 23[2], 163-5)