Magnetic properties of TbFe amorphous alloys deposited on Kapton: Optical tape feasibility

TbFe alloys in a tri-layer structure with AlN as the protective layer, deposited on a non rigid substrate (Kapton) have been studied. We have demonstrated the persistence of magnetic and magneto-optical properties on such a subtrate for instance: the anisotropy, perpendicular to the film plane and the polar Kerr rotation. A comparison is made between the properties of samples deposited on glass and those deposited on Kapton. We have demonstrated that the magneto-elastic effect is not the main component of the anisotopy. This explain why the perpendicular Kerr effect still exists. We have also shown that strains do not affect the magnetic domain characteristics. The sensitive layer has a bilayer stucture which allows us to reach a Kerr rotation as high as 0.6°. So, the validity of an optical tape concept based on the magneto-optical principle has been demonstrated.