Exchange interaction effect of TbCo/FePt bilayers

Interlayer exchange coupling in dc-magnetron sputtered Tb29.6Co70.4/FePt bilayers with different annealing temperatures of the FePt film have been investigated. The dependence of ordering degree on perpendicular magnetic properties of the FePt film was studied. The Tb29.6Co70.4/FePt film has high perpendicular coercivity and high saturated magnetization about 7.5 kOe, and 302 emu/cm3, respectively as the substrate temperature is 500 °C and annealing at 500 °C for 30 min. It also shows a strong exchange coupling between this FePt layer and Tb29.6Co70.4 layer. We also examined the interface wall energy in the exchange coupled Tb29.6Co70.4/FePt double layers.