S. Sahu; V. Devulapalli; S. Saood; G. Dehm; J.P. Best
Scripta Materialia 271 (2026) 117000
Focused ion beam (FIB) milling is a common technique for microscale fabrication, however, this method is also known to alter the surface defect properties, affecting mechanical deformation response. This study investigates the effects of Ga⁺ and Xe⁺ sources on the mechanical response of ‘near dislocation free’ Hematite α-Fe₂O₃ single crystals using micropillar compression with samples oriented along [0001], [0-110], and [5-502] compression axes. Although the extent of difference in mechanical properties between Ga+ and Xe+FIB varied across crystallographic compression directions, the critical resolved shear stress (CRSS) measured in Xe+ FIB was consistently higher. This marked difference in CRSS was attributed to microstructural differences and higher interaction volume in Ga+ compared to Xe+ FIB. The anisotropic response of the ion beam damage on CRSS has also been reported.