Magnetic Properties and Microstructure of [FePt/Ag]n MultilayerFilms

• Main Authors: Chun-Lin Ou, 歐春麟
• Other Authors: Jai-Lin Tsai
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/35079071397493213644

碩士 === 國立中興大學 === 材料科學與工程學系所 === 97 === We fabricated [FePt/Ag]3 multilayer films by DC magnetron sputtering on Corning glass substrates at high temperature post annealing using rapid thermal processing. By varying FePt film thickness, annealing temperature and insertion of the Ag thickness could be transfer orientation of magnetic moment arrangement of FePt grains from parallel to perpendicular the film and obtain similar (001) texture. Compared with annealing in different working gases atmosphere, the ordering degree and relative intensity of (00l) diffraction peaks were both promoted when annealing under Ar pressure. After 800℃annealing, [FePt/Ag]3 multilayer film showed the higher (001) preferred orientation by the FePt layers total thickness from 15 nm to 6 nm thick. [FePt 2 nm/Ag 0.5 nm]3 multilayer film was disordered fcc phase at annealing temperature 500℃ for 5 min, the coercivity (Hc⊥) only 200 Oe. When increasing annealing temperature to 800℃, film transformed to ordered fct structure and Hc⊥ increased to 13.01 kOe, led (001) oriented grains along the film normal direction that were more stable growth than others, hysteresis loop exhibited excellent perpendicular magnetic anisotropy. The increase of thickness for inserted Ag layer in [FePt/Ag]3 multilayer film reduced the ordering temperature and increased the coercivity, but destroyed development degree of (001) texture. The grains of [FePt 2 nm/Ag 0.5 nm]3 multilayer film were continuous and small by annealing at 600℃ for 5 min. The grains of film at annealing temperature 800℃ were obvious growth and formed the network structure in TEM images. The Ag atoms were diffused up the film surface by XPS depth profiling, [FePt 3 nm/Ag 0.5 nm]3 multilayer film annealing in Ar atmosphere at 700℃ for 5 min, the FePt grain average size was larger than multilayer film annealing in vacuum.