Structural and transport properties of ferromagnetically coupled Fe/Si/Fe trilayers

Abstract

We report structural, transport, and magnetic studies on ion beam deposited Fe(30,50 Å)/Si(15,20,25,30,40 Å)/Fe(30,50 Å)Fe(30,50 Å)/Si(15,20,25,30,40 Å)/Fe(30,50 Å) trilayers. Grazing incidence x-ray reflectivity, grazing incidence x-ray diffraction, and x-ray photoelectron spectroscopy techniques are used to characterize the trilayers. From these studies we infer the formation of silicide interlayers at both Fe/Si and Si/Fe interfaces. Above 25 Å25 Å nominal thickness of the Si layer, a uniform density layer of pure Si is formed. But below 25 Å25 Å nominal thickness of Si layer, a nonuniform density layer of Si and silicide is found. The electrical resistance of trilayers depends on both Fe and Si layer thicknesses. Resistance decreases with the increase in temperature between 30 and 300 K. Attempts are made to analyze the temperature dependence of resistance with the help of semiconducting and electron hopping mechanisms. Magneto-optical Kerr effect results suggest that ferromagnetic correlations are established between the Fe layers of the trilayers.