Microstructures and magnetic properties of L10 FePt films deposited on NaCl-type films

A single-layered FePt film of 30 nm thickness with perpendicular magnetic anisotropy is achieved by depositing the film onto a heated Si(100) substrate at 620 degrees C. Its perpendicular coercivity (Hc(perpendicular to)), saturation magnetization (M-s) and perpendicular squareness (S-perpendicular to) are as high as 1113 kA/m, 0.594 Wb/m(2) and 0.96, respectively. The perpendicular magnetic anisotropy degrades when a 5-nm NiO film is introduced under this single-layered film. Upon further increasing the thickness of the NiO film to 10 nm, the Hc(perpendicular to) of the single-layered film decreases greatly to around 330 kA/m. Compared to a NiO underlayer, the Hc(perpendicular to) of the FePt film remains above 1000 kA/m when a 10-nm MgO underlayer is introduced. Furthermore, when the thickness of the MgO underlayer is decreased to 5 nm, the perpendicular magnetic anisotropy of the single-layered FePt film is further enhanced. Its Hc(perpendicular to) stays high at 1081 kA/m; however, S-perpendicular to increases significantly to 1. (C) 2013 Elsevier B. V. All rights reserved.