Nanoscale analysis of electron irradiation-enhanced diffusion process on the multilayer interfaces of W-Al2O3-Ti/Cu

Structural change in nanoscale due to radiation-enhanced diffusion on the multilayers of W-Al2O3-Ti/Cu was investigated. Cross-cut thin foils of multilayer specimens were prepared using a focused ion beam. Electron irradiation was carried out in a high voltage electron microscope at 1 MV, where the temperature was at 300, 473 and 623 K. The phases of W, Al2O3 and Ti films deposited were identified from selected area diffraction patterns as bcc polycrystalline, amorphous structure and hcp polycrystalline, respectively. No structural changes for W and Ti were observed during irradiation; however, the amorphous Al2O3 transformed to crystalline γ-Al2O3 Due to electron irradiation, no diffusion was confirmed at the interface of W/Al2O3 On the other hand, inter-diffusion was recognized at the Al2O3 and Ti/Cu interfaces under irradiation.