| Pt/Co multilayers (MLs) have attracted much attention for their potential application as high-density reversible magneto-optical (MO) recording media due to their perpendicular magnetic anisotropy (PMA), high coercivity, square hysteresis loops, and large Kerr rotations. To elucidate the fundamental origin of the perpendicular magnetic anisotropy in such multilayers several mechanisms were proposed: the Ned surfaces anisotropy, magnetoelastic energy due to lattice mismatch, crystalline anisotropy, and electronic structures. G. A. Bertero has also suggested that the (Pt/Co/Pt) trilayers can be used as a unit in combination with nonmagnetic layer, X (X=~Pd, Ag, Cu, and Ni), to enhance the perpendicular magnetic anisotropy of the films. Furthermore, it was also found that the Curie temperature of (PtICo/Pt)Ni film was largely reduced, and the Kerr rotation was enhanced at lower wavelengths, compared with pure Pt/Co film. Moreover, recent studies found that the interlayer coupling in FM/Semiconductor/FM trilayers exhibits quite differently from the usual metal/metal superlattices, i.e., the coupling changes from FM coupling to AF coupling, then non-coupling with the increase of Si thickness up to 20 A. The coupling strength was also found very sensitive to the composition of the amorphous semiconductor spacer. It was also revealed that the amorphous Si seed layers could enhance the coercivity, squareness of Kerr loop, the perpendicular anisotropy and reduce the recording noise of Pt/Co multilayers. Other researches also found that the perpendicular anisotropy of Pt-Co alloy films could also be suppressed by trace of amount of Si. It was also pointed out that the spin-polarized transport in FM/Semiconductor systems has the potential to create a variety of spin electronic devices. All these researches indicate a very interesting research field of the magnetic behavior of ferromagnetic films at the presence of semiconductors. In this paper, we have investigated the effects of intercalating Si into the Pt layers on the magnetic and magneto-optical properties of the 2.4A Co/9 A Pt multilayers. Such studies may provide a better understanding of the magnetic interactions between the magnetic elements cross the semiconductor spacer, and its effect on the perpendicular magnetic anisotropy (PMA) and magneto-optical Kerr effect (MOKE) in Pt/Co MLs. Si/(PtICo/Pt) modulated multilayers have been prepared by magnetic sputtering method with the thickness of Si layers d51 varying from 0 to 16 A. The background vacuum was better than 5 X iO~ Pa and the Ar gas pressure was 0.5 Pa. All samples were grown on a 450 A thick Pt buffer layer, with the thickness of Co and Pt layers fixed at 2.4 A and 4.5 A, respectively. The number of the modulation period of all samples is 20. The modulation character and III L Abstract interface structures of the samples were analyzed by small- and large-angle X-ray diffraction (XRD) method. The magnetic properties were characterized using an alternating gradient force magnetometer (AGM) with the applied magnetic field perpendicular to the film plane. The effective perpendicular anisotropy constant K,~ff was determined from torque curves measured at an applied field of 10 kOe at room temperature. The domain structure of the samples in DC-demagnetized state has been inv... |
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