Phase transformation of Co into CoF3 by XeF2 - assisted Focused Electron Beam Induced Processing
SONDERTERMIN: Frau M.Sc. Paulina Holuj (Universidad de Zaragoza, 50018 Spain)

Abstract Focused Electron Beam Induced Processing (FEBIP) using XeF₂ gas injection is routinely applied in circuit editing, mask reparation and nanolithography to etch materials such as SiO₂, Si₃N₄, Al₂O₃, Cr, Ta, GaAs, Ti, etc. In present studies, we report the use of XeF₂ ? assisted FEBIP for a novel application: the phase transformation of materials . Our research focused on the in?uence of XeF₂ on Co deposit. We observed the transformation of cobalt into cobalt tri?uoride (CoF₃) that exhibits antiferromagnetic behavior at room temperature.
In present studies quite broad compositional analysis of prepared nanostructures was carried out. EDX analysis provided qualitative information about the presence of cobalt ?uoride. Whereas more advanced techniques, available in TEM, like EELS and HRTEM allowed us for di?erentiation between two stable cobalt ?uorides (CoF₂ and CoF₃).
The studied system consists of ferromagnetic (Co) and antiferromagnetic (cobalt ?uorides) layers (FM-AFM). Exchange bias, appearing in that bilayer system may be utilized in devices like: magnetic recording media, domain stabilizer in recording heads or 'spin-valve' devices. These studies may provide bases for further research aimed at fabrication of such devices based on Co-CoF₃ system using FEBIP.