材料期刊网

The films with HM=(Pr,Dy)(Fe,Co,Nb,B)(5.5) and SM=Fe, FeCo were prepared by sputtering and subsequent heat treatment. The coercivity of Ti-buffered (Pr,Dy)(Fe,Co,Nb,B)(5.5) single-layer film with 320 nm thickness is as large as 18.8 kOe at room temperature. X-ray diffraction results reveal that the Pr2Fe14B-type phase is randomly oriented in almost all the multilayer films. For the multilayers of Ti(30 nm)/[HM(16 nm)Fe(x nm)]x20/Ti(30 nm)/Si(substrate), the remanence increases and the coercivity decreases with the addition of Fe content, in comparison with the results of the single-layer film and the maximum energy product of 14.8 MGOe is obtained at x=3.0. A noticeable shoulder on the demagnetization curve is observed at low temperatures. When Fe65Co35 is used as the SM component rather than Fe, similar results are found. The enhancement of the magnetic properties in the nanocomposite multilayer films is explained by means of the exchange coupling between the SM and/or HM nanograins of the intra- and interlayers. (C) 2003 American Institute of Physics.