Hall Effect in Fe–Cr–Co Alloy Thin Films

This paper presents the Hall effect and microstructure of Fe– X Cr–10Co, Fe– X Cr–Co (weight ratio W F e / W C o =1), and Fe–60Cr– X Co alloy films. After deposition by ion beam sputtering (IBS), the Hall voltage ( V H ) and Hall coefficient ( R H ) values of the as-deposited films were found to be small. After heat treatment, phase separation into α 1 (ferromagnetic phase) and α 2 (paramagnetic phase) was observed and verified by high resolution transmission electron microscope (HRTEM). By aging the Fe–60Cr–15Co films at 550° C for 80 min, we found the maximum Hall resistivity (ρ H ) and Hall voltage ( V H ) values which are 30 µ Ω· cm and 1.2 mV, respectively (measured at 77 K and 14 kOe). The extraordinary Hall coefficient ( R S ) is about 0.408 cm 3 /C. The Hall coefficient is positive for both as-deposited and annealed films. The alloy composition and heat treatment condition which influence film's microstructure obviously affect the Hall property.