Hall Effect in Fe–Cr–Co Alloy Thin Films

Abstract
This paper presents the Hall effect and microstructure of Fe–XCr–10Co, Fe–XCr–Co (weight ratio W F e/W C o=1), and Fe–60Cr–XCo 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 α1 (ferromagnetic phase) and α2 (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 cm3/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.