Interface mediated control of microstructure and magnetic properties of FePt-C thin films

The microstructure and magnetic properties of FePt-C film deposited on the MgO/CrRu underlayer are studied in lieu of carbon doping in FePt and RF biasing assisted etching of the MgO underlayer. Increasing amounts of carbon doping in the FePt deteriorates the chemical ordering as a result of reduced kinetic energy of FePt adatoms due to frequent collision with carbon adatoms. This leads to a reduction in the magnetocrystalline anisotropy energy and hence the coercivity. RF etching of the MgO/CrRu underlayer before deposition of FePt helps to reduce the grain size and intergranular exchange interaction without adversely affecting the chemical ordering. Reduced intergranular exchange interaction leads to an increase in the coercivity. - Highlights: → In this paper microstructure and magnetic properties of FePt-C film are studied. → Increasing amounts of carbon doping in the FePt deteriorates the chemical ordering. → RF etching of the MgO/CrRu underlayer helps to reduce the grain size. → RF etching of the MgO/CrRu underlayer reduces intergranular exchange interaction. → Reduced intergranular exchange interaction leads to an increase in the coercivity.