2005 Volume 46 Issue 8 Pages 1802-1806
Structural properties of CoPtCr–SiO2 magnetic recording films grown on Ru or Pt seed layers prepared by UHV-magnetron sputtering were studied by high resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy (EELS) and energy filtered transmission electron microscopy (EFTEM). CoPtCr grown on Ru seed layers together with SiO2 forms a well-isolated structure composed of CoPtCr fine grains of 10 nm diameter surrounded by amorphous SiO2, whereas CoPtCr grown on Pt seed layers together with SiO2 forms a network structure composed of CoPtCr crystal of 5 nm size. These structural features made differences in their magnetic properties. The HRTEM and EFTEM studies revealed that cylindrical crystalline grains composed of CoPtCr and Ru are formed for CoPtCr–SiO2/Ru samples, whereas SiO2 are aggregated around the boundary between relatively large Pt grains and magnetic layers without obstructing the epitaxial growth of CoPtCr on Pt, not resulting in the cylindrical CoPtCr grains. Lattice spacings of CoPtCr grown on Pt with SiO2 are 0.7% expanded in comparison with CoPtCr grown on Pt without SiO2. The EELS studies suggested that Co and Cr atoms are partly oxidized by SiO2 addition for both samples and Cr atoms are more oxidized for CoPtCr–SiO2/Pt samples.
