Microstructure and magnetic properties of interfacially disordered FePt particles

In order to clarify the effect of the interfacially disordered layer on the magnetic properties, we have investigated the magnetic properties of L1₀ FePt particles with a thin disordered interface. 10 nm FePt films were deposited on MgO [001] single crystal substrates at 700°C using a multiple de-sputtering system. A 5 nm amorphous Al₂O₃ layer was subsequently deposited at room temperature. Magnetization were measured by a SQUID magnetometer with and without the Al₂O₃ layer. The microstructure and film morphology were characterized by TEM. A change of magnetization reversal mechanism due to the presence of the soft disordered layer was observed.