Pulsed laser deposition of barium hexaferrite (BaFe12O19) thin films

Hexagonal thin films of barium hexaferrite (BaFe 12 O 19 ) were fabricated by pulsed laser deposition (PLD) on sapphire substrates. The films were grown in oxygen atmosphere by two different pulsed excimer lasers: a XeCl * (A = 308 nm, τ FWHM ≤ 30 ns) and a KrF * (A = 248 nm, τ FWHM ≥ 20 ns) laser in the temperature range 500-750°C. The experiments showed that the heating temperature is a key parameter in determining the films' magnetic characteristics. Some of the films were laser annealed with an Nd:YAG laser (λ = 1064 nm). High coercivity H c = 3.6 kOe and good hysteresis shapes were obtained. An anisotropy of the coercive force H c , saturation magnetization M s and remanent magnetization M r was observed. The magnetic measurements were correlated with the structural and compositional characterization performed by X-ray diffraction (XRD), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS).