Effect of Annealing on Extraordinary Hall Effects in Sputtered Granular Cu80Co20 Thin Films

The work focuses on the extraordinary Hall effect (EHE) properties of annealed Cu₈₀Co₂₀ thin films by examining the magneto-transport in a series of thin films with vol.20% Co annealed at various temperatures. The films were sputtered on Si at base pressures below 1.5 times 10^-7 Torr. Thinner films of 40 nm were made for Hall effect measurements while thicker films of 105 nm were made for magnetic measurements. These films were patterned into standard Hall bars followed by subsequent ex-situ annealing in vacuum chamber at temperatures ranging from 100 to 500degC for 60 minutes. The SQUID magnetometer was used to measure magnetic susceptibilities (chi-T) versus temperature, followed by magnetic hystereses (M-H) in a cyclic field ranging from -5.0 to +5.0 Tesla at 10 and 300 K. The magneto-transport was measured in a magneto-measurement system in a cyclic field ranging from -8.00 to +8.00 Tesla.