Electrical and structural properties of InSb crystals irradiated with reactor neutrons

The structural transformations in InSb crystals irradiated with fast neutrons (E>0.1MeV) and the full spectrum of reactor neutrons with the ratio of the slow to fast neutron fluxes ϕsn/ϕfn≈1 are studied. Two ranges on the dose dependence can be selected according to the influence of fast neutron irradiation on the lattice parameter. Increase of the lattice parameter is not observed at the low flux (Ffn<2.5×1017cm-2). As it follows from the X-ray diffuse scattering analysis, vacancy-type clusters dissociate in this range, and the number of small interstitial-type clusters simultaneously increases in this range. At Ffn>2.5×1017cm-2 the lattice parameter linearly increases with flux. A great number of small interstitial- and vacancy-type clusters, which can trap Sn impurity atoms, are formed. The heat treatment of irradiated samples up to 400 °C completely recovers the values of the lattice parameter.