X-ray study of the relation between the coercivity and atomic structural properties of the epitaxial Co/Pt multilayers on Al2O3(1 1 –2 0) substrates

Abstract The relation between the coercivity and the structure of MBE (Co/Pt) 30 multilayers on Al 2 O 3 (1 1 –2 0) with Pt buffer layers was studied. By changing the thickness of Co layers, Pt layers or Pt buffer layers, the in-plane strains of Pt layers can be varied from −1.6% to −4.5%. The coercive force, H c , is roughly inverse proportional to the in-plane strain of Pt layer. However, if the in-plane strain is constant, the H c is still increased regardless of the decrease of the density of the in-plane defects as the thickness of the Pt buffer layer increases. The interface mixing might be the reason of reducing the H c value.