Structural and Magnetic Properties of FeCuNbSiB Thin Films Deposited by HiPIMS

Using high-power impulse magnetron sputtering (HiPIMS) technique, Fe_73.5Cu₁Nb₃Si_15.5B₇ thin films with thickness between 40 and 700 nm were deposited. The influence of deposition conditions (deposition time and argon pressure) and of the annealing temperature on the structure and coercive magnetic field of the magnetic films was analyzed. In the as-deposited state, the coercive magnetic field presents a minimum at about 10 mtorr argon pressure. The X-ray diffraction studies show that in the as-deposited state, the samples are amorphous, while after annealing at temperatures between 400°C to 525°C, α-Fe(Si) grains start to nucleate, the grain size varying from 2 to 18 nm. The Curie temperature of as-deposited amorphous phase and the onset of the primary crystallization are 355°C and 460°C, respectively. The lowest coercive magnetic field was obtained after annealing at 475°C.