Orientation control in L10 FePt films by using magnetic field annealing around Curie temperature

A new method to improve (0 0 1) texture of L10 FePt films was reported. In this work, in order to obtain the perpendicular orientation of L10 FePt films, the FePt films were annealed at 700 °C (TA1) for 30 min and then annealed at TA2 (430–600 °C) for an hour either in a magnetic field of ∼3500 Oe along the normal direction of the films (Route A) or without magnetic field (Route B). Compared with the Route B, I(0 0 1)/I(1 1 1) showed a peak value of 7 when TA2 was around 478 °C (around the Curie temperature of L10 FePt films) and the AFM image of FePt sample was annealed around 478 °C showed an obvious change of grains through Route A. It is related to the following reason: when the temperature is near Curie temperature of L10 FePt films, the thermal disturbing term is close to the exchange energy of the magnetization, therefore, the magnetic field of ∼3500 Oe is effective for promoting the preferential growth direction of L10 structure.