SHORT-RANGE ORDER EFFECTS IN AMORPHOUS FEXSI1-X SI MULTILAYERS INDUCED BY PREPARATION CONDITIONS/

Magnetic properties of compositionally modulated FexSi1-x/Si amorphous multilayers are reported. The concentration x was 0.68 less than or e qual to x less than or equal to 0.82 for two nominal modulation length s lambda of 4 and 8 fi. The samples were prepared by pulsating two-cat hode sputtering. From SQUID magnetometry and transverse magneto-optic Kerr effect, we detected a noticeable decrease in both magnetization a nd relative reflectivity (delta=Delta R/R) as lambda increases from 4 to 8 Angstrom. Also, for a fixed value of x, it was found that both co ercive field and in-plane uniaxial anisotropy constant decrease system atically for increasing lambda. The two pulses used in the preparation method causes slight chemical short range effects, altering also the magnetic properties by changing the number and nature of nearest neigh bors of a given Fe atom. The above short-range effects are present eve n when no multilayer structure is detected by x-ray diffraction.