Preparation of strontium hexaferrite film by pulsed laser deposition with in situ heating and post annealing

Strontium hexaferrite (SrFe12O19) films have been fabricated by pulsed laser deposition on Si(1 0 0) substrate with Pt(1 1 1) underlayer through in situ and post annealing heat treatments. C-axis perpendicular oriented SrFe12O19 films have been confirmed by X-ray diffraction patterns for both of the in situ heated and post annealed films. The cluster-like single domain structures are recognized by magnetic force microscopy. Higher coercivity in perpendicular direction than that for the in-plane direction shows that the films have perpendicular magnetic anisotropy. High perpendicular coercivity, around 3.8 kOe, has been achieved after post annealing at 500 degrees C. Higher coercivity of the post annealed SrFe12O19 films was found to be related to nanosized grain of about 50-80 nm. (C) 2012 Elsevier B.V. All rights reserved.