垂直取向FePt/Ag纳米颗粒薄膜的结构和磁性

用磁控溅射法在单晶MgO(100)基片上制备了［FePt 2 nm/Ag dnm］₁₀多层膜， 经真空热处理后，得到具有高矫顽力的垂直取向L1₀-FePt/Ag颗粒膜.x射线衍射结 果表明，在250 ℃的热基片上溅射，当Ag层厚度d=3—11 nm时，FePt颗粒具有很好的［001］取向，随着Ag层厚度的增加，FePt颗粒尺寸减小.［FePt 2 nm/Ag 9 nm］₁₀经过6 00 ℃真空热处理15 min后，颗粒大小仅约8 nm，垂直矫顽力达到692 kA/m.这种无磁耦合作用的颗粒膜，适合用作超高密度的垂直磁记录介质. 关键词： 磁控溅射 垂直磁记录 纳米颗粒膜 0-FePt/Ag')" href="#">L1₀-FePt/Ag

Structure and magnetic properties of FePt/Ag nano-granular films with perpendicular magnetic anisotropy

［FePt 2 nm/Ag d nm］₁₀ (d=0—11) multilayers were prepared on single crystal MgO(100) substrates kept at room temperature and 250 ℃ by means of magnetosputtering. L1₀-FePt/Ag granular films with perpendicular magn etic anis otropy and high coercivity have been obtained after vacuum annealing the multila yers deposited on substrates kept at 250 ℃ for 15 min. X-ray diffraction result s indicate that FePt particles have a strong ［001］ orientation. The size of Fe Pt particles decreases with the increase of the thickness of Ag layer. After vac uum annealing the ［FePt 2 nm/Ag 9 nm］₁₀ films at 600 ℃ for 15 min, FePt /Ag granular films are obtained with only 8 nm of particle size and 692 kA/m of coercivity. Isothermal magnetization remanence and dc-demagnetization remanence measurements show that no magnetic exchange coupling between magnetic particles can be observed. Such a kind of films is suitable for future ultra-density perp endicular magnetic recording medium.