Abstract
Perpendicular magnetic anisotropy and magnetic domain structure were studied in epitaxial [Co(t Co )/Pt(10 angstroms)] 30 (t Co = 2, 2.5, 3, 4, 5 and 10 angstroms) multilayers prepared on Al 2 O 3 (1 1 -2 0) substrate via Mo or Pt seed layer. The best perpendicular magnetic effect occurred for t Co to approximately 3 angstroms. At remnant state the domain size tends to increase as t Co decreases, and the domain structure depends strongly on the seed layer. For [Co(3 angstroms)/Pt(10 angstroms)] 30 multilayers grown on gold grid made hole arrays, the polar coercivity inside the holes is different from those on the gold land and unpatterned area.