FIM試料の不活性ガスイオン照射によるWの原子変位エネルギーの測定
1971 年 40 巻 4 号 p. 380-390
詳細
1971 年 40 巻 4 号 p. 380-390
Tips of FIM tungsten specimens were irradiated with 0. 5 to 9 keV inert gas ions, which were emitted from a field-ion gun attached to a side of the FIM tube. The threshold voltage of ion acceleration at which surface damages appeared was determined through a direct observation of FIM images. This determination made it possible to estimate the displacement energy of surface atoms on tungsten to be about 22 eV. From this value the displacement energy of bulk atoms of the same material was estimated to be 30 to 35 eV.
By examining FIM images with particular attention to the stability of surface atoms on the field-evaporated specimen tips, some informations were obtained concerning the process of formation of surface damages. The flight range of penetrating inert gas ions in tungsten was also calculated by the LSS theory. The result indicated that surface damages which appeared on the side of the tip apex counter to the ion-injected one might be ascribed to the channeling of gas ions to the ‹110› direction in tungsten.
