Springer LINK: The European Physical Journal B - Abstract Volume 5 Issue 1 (1998) pp 61-66

The European Physical Journal B

ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)

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Abstract Volume 5 Issue 1 (1998) pp 61-66

Magnetic and transport properties of sputtered Fe/Si multilayers

L.N. Tong (1), M.H. Pan (1), J. Wu (1), X.S. Wu (1), J. Du (1), M. Lu (1), D. Feng (1), H.R. Zhai (1) (a), H. Xia (2)

(1) Center of Materials Analysis and National Laboratory of Solid State Microstructures, Nanjing University, CASTM, Nanjing 210093, P.R. China
(2) General Research Institute for Nonferrous Metals, Beijing, 100088, P.R. China

Received: 11 February 1998 / Revised: 9 March 1998 / Accepted: 9 March 1998

Abstract: The structural, magnetic and transport properties of sputtered Fe/Si multilayers were studied. The analyses of the data of the X-ray diffraction, resistance and magnetic measurements show that heavy atomic interdiffusion between Fe and Si occurs, resulting in multilayers of different complicated structures according to different sublayer thicknesses. The nominal Fe layers in the multilayers generally consist of Fe layers doped with Si, ferromagnetic Fe-Si silicide layers and nonmagnetic Fe-Si silicide interface layers, while the nominal Si spacers turn out to be Fe-Si compound layers with additional amorphous Si sublayers only under the condition either $\ensuremath{{\it t}_{\mathrm{Si}}}\ge 3 \mathrm{nm}$ for the series $\mathrm{[Fe(3 nm)/Si( \ensuremath{{\it t}_{\mathrm{Si}}})]_{30}}$ or $\ensuremath{{\it t}_{\mathrm{Fe}}}< 2 \mathrm{nm}$ for the series $\mathrm{[Fe( \ensuremath{{\it t}_{\mathrm{Fe}}})/Si(1.9 nm)]_{30}}$ multilayers. A strong antiferromagnetic (AFM) coupling and negative magnetoresistance (MR) effect, about 1%, were observed only in multilayers with iron silicide spacers and disappeared when $\alpha$-Si layers appear in the spacers. The dependences of MR on \ensuremath{{\it t}_{\mathrm{Si}}} and on bilayer numbers N resemble the dependence of AFM coupling. The increase of MR ratio with increasing N is mainly attributed to the improvement of AFM coupling for multilayers with N. The \ensuremath{{\it t}_{\mathrm{Fe}}} dependence of MR ratio is similar to that in metal/metal system with predominant bulk spin dependent scattering and is fitted by a phenomenological formula for GMR. At 77 K both the MR effect and saturation field $H_{\mathrm{s}}$ increase. All these facts suggest that the mechanisms of the AFM coupling and MR effect in sputtered Fe/Si multilayers are similar to those in metal/metal system.

PACS. 72.15.Gd Galvanomagnetic and other magnetotransport effects - 73.40.Sx Metal-semiconductor-metal structures

(a) email: hrzhai@netra.nju.edu.cn

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