Enhanced Magnetization at the Interface in Fe83Tb17/Pt Multilayers

Fe 83 Tb 17 /Pt multilayers with different Fe 83 Tb 17 thicknesses (50 ≤ t FeTb ≤ 200 Å) were prepared using sputtering technique, and their magnetic and magneto-optical properties were investigated. With decreasing Fe 83 Tb 17 thickness ( t FeTb ) below 200 Å, the saturation magnetization and the polar Kerr rotation of the multilayers were found to increase. It is found that the interfacial layer with an extended thickness of 10 Å presents a larger magnetization than that of the bulk layer. The magnitude of the magnetization of the interfacial layer suggests that it is rich in Fe with a chemical formula of FePt. Polar Kerr rotation measurements support this scenario. In addition, the out-of-plane magnetic anisotropy was found to decrease with decreasing t FeTb , with a transition to an in-plane magnetization alignment at low Fe 83 Tb 17 thicknesses.