Defect production in Bi and dilute alloys irradiated by electrons

Pure bismuth and dilute bismuth alloys (containing tellurium or tin) were electron irradiated at high doses. In most experiments the resistivity was measured during defect production; for some experiments the magnetoresistance and Hall effect were also studied. We analyze the data from this latter experiment type, which enables us to know the variation of the carrier number during irradiation, i.e., the mean charge brought by a defect. The results are in agreement with a simple model which states that the Frenkel pairs are of donor type and are ionized under all circumstances whereas the more complicated defects created at high electronic energy (above 1.2 MeV) are of acceptor type and produce in the density of states a virtual bound state situated slightly below the pure bismuth (intrinsic) Fermi level. These results are in agreement with the conclusions of an earlier paper in which we studied the displacement threshold energy in bismuth. Moreover, our data enable us to state that the recombination volume in bismuth is in the 100--200 atomic volume range