Defects induced by 5 and 9.5 MeV fast neutron irradiations in N-type HB single crystal GaAsare studied by the positron annihilation lifetime technique.Mono-and di-vacancies are created for the neu-tron irradiation to ...Defects induced by 5 and 9.5 MeV fast neutron irradiations in N-type HB single crystal GaAsare studied by the positron annihilation lifetime technique.Mono-and di-vacancies are created for the neu-tron irradiation to a fluence of 10<sup>13</sup> n/cm<sup>2</sup> and only rnono-vacancies are produced for the neutron irradia-tion to a fluence of 10<sup>11</sup>～10<sup>12</sup>n/cm<sup>2</sup>.It is found that the higher the irradiating neutron energy and flu-ence,the higher the intensity of the produced defects.As a result the defect production rate becomes in-creasingly more sensitive to the neutron fluence than to the neutron energy.The annealing behavior of thedefects is also investigated up to 750℃.Tri-vacaneies are formed between 450 and 620℃ in GaAs irra-diated to 10<sup>13</sup> n/cm<sup>2</sup> by 9.5 MeV neutrons.Three annealing stages are observed for the mono-,di-andtri-vacancies.展开更多
文摘Defects induced by 5 and 9.5 MeV fast neutron irradiations in N-type HB single crystal GaAsare studied by the positron annihilation lifetime technique.Mono-and di-vacancies are created for the neu-tron irradiation to a fluence of 10<sup>13</sup> n/cm<sup>2</sup> and only rnono-vacancies are produced for the neutron irradia-tion to a fluence of 10<sup>11</sup>～10<sup>12</sup>n/cm<sup>2</sup>.It is found that the higher the irradiating neutron energy and flu-ence,the higher the intensity of the produced defects.As a result the defect production rate becomes in-creasingly more sensitive to the neutron fluence than to the neutron energy.The annealing behavior of thedefects is also investigated up to 750℃.Tri-vacaneies are formed between 450 and 620℃ in GaAs irra-diated to 10<sup>13</sup> n/cm<sup>2</sup> by 9.5 MeV neutrons.Three annealing stages are observed for the mono-,di-andtri-vacancies.
