FePt: Al2O3 nanocomposite thin films synthesized by magnetic trapping assisted pulsed laser deposition with reduced intergranular exchange coupling

FePt : Al2O3 nanocomposite thin films synthesized by magnetic trapping (MT) assisted pulsed laser deposition (PLD) were found to have lower transition temperature for L10 face-centred-tetragonal (fct) phase due to higher concentration of defects. The low phase transition temperature together with non-magnetic matrix materials helps to reduce grain growth and agglomeration during annealing. Small remanence ratio and coercive squareness for nanocomposite thin films annealed at 300 °C to fct phase confirm that the main intergranular interaction is magnetostatic interaction rather than exchange coupling. The MT assisted PLD can synthesize fct-FePt : Al2O3 nanocomposite thin films with reduced intergranular exchange coupling.