Structure, magnetic, and transport properties of sputtered Fe/Ge multilayers

摘要

The structure, magnetic, and transport properties, especially the Hall effect, of Fe/Ge multilayers fabricated by magnetron sputtering were investigated. Structure characterization indicates a periodic modulated structure with alternately deposited polycrystalline Fe and amorphous Ge layers. The room-temperature magnetic measurements reveal that the uniaxial magnetic anisotropy K_u of the Fe/Ge multilayers with a period of 5.2 nm is 2.27×10~3 J/m~3. The temperature coefficient of resistivity of all the films is positive at room temperature but turns to be negative at low temperatures due to the weak localization effect. The Fe/Ge multilayers show anomalous Hall effect and the Hall sensitivity K_H is independent of the temperature, showing that Fe/Ge multilayers have the potential applications in the field of magnetic sensors. When the period Λ is 5.2 nm, the anomalous Hall coefficient R_s reaches its largest value of 1.8×10~(-7) Ω m/T, which is three orders of magnitude larger than that of the bulk Fe material.