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We have investigated the lattice disorder produced in Si by 200-keV B implantations using the standard channeling technique. We found the disorder production strongly temperature-dependent from about −85°C to room temperature. The annealing of the residual disorder present after such a B implantation takes place at higher temperatures. Our results indicate that the nature of the lattice disorder produced in Si by low dose ion implantation depends on the mass of the ion implanted.

The temperature dependence of lattice disorder created in Si by 40-keV Sb ions was studied by energy analysis of the yield of backscattered 1-MeV He ions incident along 〈111〉 and 〈110〉 axes. Doses of ∼ 1 × 1013 Sb ions/cm2 were used so that the disorder level was below that representing an amorphous layer. The disorder per incident ion decreases strongly with implant temperature above 50°C. This is approximately 100°C lower than the region of corresponding decrease in the anneal of a low-dose room-temperature implantation. For implantation temperatures less than 50°C, the disorder per ion was only mildly temperature-dependent.

Ferritic alloys have some promise for duct and cladding applications for liquid metal fast breeder reactors (LMFBR) because of their favorable neutron absorption cross sections. Two alloys of the 10 to 12 percent chromium class, EM-12 and HT-9, have been selected for study in the National Alloy Development Program. Bombardment with 2.8 MeV 56Fe+ ions and transmission electron microscopy (TEM) observations were used to determine the temperature dependence of swelling at 150 displacements per atom (dpa) and the swelling rate at the peak swelling temperature up to 250 dpa. Both alloys were found to be more swelling resistant than Type 316 stainless steel, with EM-12 having a swelling rate of 0.011 percent/dpa at the peak swelling temperature of 550°C (1022°F) while HT-9 had a swelling rate of 0.017 percent/dpa at the peak swelling temperature of 500°C (932°F). An unusual feature of swelling in these materials was the formation of very large voids on precipitates along the grain boundaries.