Effects of Laser Spot Size on the Microstructure and Magnetic Properties of PLD Fabricated Fe-Co Films

Fe-Co films are prepared by using a pulsed laser deposition (PLD) method with several diameters of a laser beam. It was found that the usage of an Fe-Co alloy target together with a small spot size, which means that a laser beam was focused on the surface of a target, enables us to reduce the number and/or size of droplets and improve the surface roughness of samples. The transfer of composition from a target to the corresponding film deteriorated as the diameters of a laser beam decreased. Furthermore, an as-deposited Fe-Co film prepared by using the small spot size had a magnetization of approximately 2.4 T at the applied magnetic field of 1400 kA/m.