Microstructure and magnetic properties of L10 FePt–MgO/Fe–MgO thin films

The L10 FePt–MgO/Fe–MgO bilayers were fabricated on thermal oxide silicon substrate by using magnetron sputtering. The TEM image shows that the FePt–MgO single layer has small and uniform granular grain. In the FePt–MgO/Fe–MgO bilayer system, with increasing Fe layer thickness, the grain size become larger and the grain boundary become obscure, while the magnetization process transforms from a coherent magnetization to an exchange spring behavior, and finally a two-phase magnetization reversible process.