Magnetic properties and structure of rare-earth-transition-metal thin films implanted with Ar + ions

Abstract

Changes in the local magnetic properties and structure of amorphous TbFe thin films, induced by ion implantation, have been investigated in comparison with amorphous GdCo thin films. The samples were obtained by rf co-sputtering on glass substrates. X-ray diffraction and Rutherford backscattering spectrometry (RBS) have been used for structural and compositional analysis. Local hysteresis loops and coercive forces were studied by magneto-optic polar Kerr effect. Structural investigations showed the films to be completely amorphous, before as well as after implantation. Magneto-optical measurements pointed to a progressive diminution of local hysteresis loop area and to a specific behaviour of the relative coercive force for TbFe and GdCo samples, with increasing dose. Both effects were explained by the alteration of magnetic properties in the implanted layer.