Preparation And Characterizaiton Of L1₀-FePt Thin Films With High （001） Orientation

In this paper, FePt thin films were prepared by magneto sputtering on Si(001) substrates.The structures，magnetic properties and surface toughness of the films were studied by X-raydiffraction (XRD), vibrating sample magnetonetry (VSM) and scanning probe microscropy(SPM). The effect of annealing method, temperature and the thickness of FePt and carbonseed layer on the structures and magnetic properties of the films were investigated.The main conclusions are as following:(1) The sample annealed in vacuum stove presented stronger (001) orientation andhigher degree of ordering, and the values of coercivity in perpendicular direction are largerthan that in parallel direction, indicating good perpendicular magnetic anisotropy. For thesample annealed in hydrogen, thin film shows the strongest (001) texture, the maximumperpendicular coercivity value, exhibiting significant perpendicular magnetic anisotropy.(2) With the increasing of annealing temperature, the grain size of FePt particles, thevalues of ordering parameters and I(001)/I(111)increased, and (001) orientation improvesgradually. The values of coercivity in perpendicular direction Hc⊥trend to rise, while Hc∥increases first then decreases.The remanence ratic in perpendicular direction is inclined toincrease while S∥displays the opposite tendency. For the sample annealed at600℃,I(001)/I(111)is equal to203, showing a strong (001) texture, while coercivity value inperpendicular direction is9.064kOe, Hc⊥-Hc∥equals8.291kOe, exhibiting the bestperpendicular magnetic anisotropy.(3) When the FePt thickness of sample films increases, the intensity of FePt (111)diffracting peaks and the remanence ratic in parallel direction increases, so value of I(001)/I(111)ratio remanence ratic in perpendicular direction, and Hc⊥-Hc∥decreases, showingweakening (001) orientation and perpendicular magnetic anisotropy. When the thickness ofFePt is10nm, the sample exhibites the best perpendicular magnetic anisotropy.(4) With the increasing of the thickness of carbon seed layers,(001)/(111) peak intensityratio and c/a ratio increase, the (001) orientation of L10-FePt thin films, the degree of ordering,the values of coervicity and remanence ratic in perpendicular direction improves. PerfectL10-FePt film with high (001) texture was obtained when the sputtering time of carbon is180s.