Laser Writing on Amorphous TbFe Films for Magnetic Printing

The laser (thermal) writing characteristics of amorphous TbFe perpendicular magnetic films of thicknesses h between 0.1 and 3 ¿m are reported. The Ms-Hc characteristics for Tb-rich and Fe-rich films were investigated; for limited film thicknesses h, Tb-rich films, with a larger magnetization, were more suitable for magnetic printing. The write power versus written reverse domain diameter was measured, and it was found that the reverse domain diameter increased geometrically with radiation power for thin (0.1 ¿m) film, but increased linearly for thicker (2.3 ¿m) film. Tb-rich film necessitates greater recording powers, and enables recording over a wide range of Ms·h values.