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

• Published in: Applied surface science Vol. 258; no. 15; pp. 5770 - 5773
• Main Authors: Liu, Liwang, Lv, Hua, Sheng, Wei, Lou, Yuanfu, Bai, Jianmin, Cao, Jiangwei, Ma, Bin, Wei, Fulin
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.05.2012; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Curie temperature; Exact sciences and technology; Exchange energy; FePt; Magnetic field annealing; Physics; Exchange energy; FePt; Magnetic field annealing; Curie temperature; Annealing; Curie point; Magnetic field effects
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2012.02.090

► We report a new method to improve (001) texture of L10 FePt films. ► Annealing at its Tc in a magnetic field is used to control the texture of FePt films. ► Why the magnetic field is effective around Tc is analyzed on viewpoint of the energy. A new method to improve (001) 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 30min and then annealed at TA2 (430–600°C) for an hour either in a magnetic field of ∼3500Oe along the normal direction of the films (Route A) or without magnetic field (Route B). Compared with the Route B, I(001)/I(111) 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 ∼3500Oe is effective for promoting the preferential growth direction of L10 structure.