Structural and Magnetic Properties of  $\text{L}1_{\textrm {0}}$ -FePt-Based Exchange Coupled Composite Films With FeRu Underlayers
The (001) textured L10-FePt thin films have been prepared on FeRu underlayers by dc magnetron sputtering. By taking the FePt layer as the top layer, the hard layer of exchange coupled composite (ECC) films is close to the magnetic head, which consequently makes the larger head field benefit the magnetic reversal of the composite. In this paper, the dependence of structural and magnetic properties of the FePt-based ECC films on the thickness of the FeRu layer is investigated.