Thermo-electric and magnetoresistive properties of Fe-Ag coevaporated thin film

Abstract

Control over the shape, size and spacing of the magnetie elements in nanoseale composites is an important issue, not only for the applications, bnt also for our basic understanding of the interactions among magnetic elemcnts. TIlCbinary metallie system Fc-Ag co-cvapomted thin film in the nano"scopic groin si~c have shown excellent Giant Magneto Re,istancc(G},ffi) effect making them suitable for magnctic recording. In the cquiJibrilUn state at room tempcratl.lrcthe grains of Fe and Ag have almost zero miscibility whieh makes it an excellent combination for GMR investigation. ill the present work an investigation of the magnetic interaction between the ferro-magnetic Fe grain and the nonmagnetic Ag grain as they arc deposited randomly on a polymer Sl.lbstrate Kapton film has been done, Its effect on the e1ectriealproperties c.g. the electrical resistivity, the mugnctoresistallce and ac magnetic pClll1eabilityhave been investigated as a function of tClllpcrarnreand freqUCtlcy. High frequcllcy permcability study is expected to provide some valuable illfonnation abont the magnetic relaxation effcct. The time dependcnt variation in the t1leIllloelectricpowcr have been srndied lISinga monochromatic light source to understand the lISeful infollnation regarding electron-phonon interaction. The X-ray diffraction pattern shows some sharp intcnsity pcaks for Ag indicating that the concentration of silver is high in thc Fc-Ag thm film for which the magnetic behavior of Fe has been suppressed. The Fo-Ag binary alloy system has paramagnetic phase at room tempcrature as the partieles are in the nanornetric scale with largc lllOlllcnts randomly oriented, However an cndured annealing of the sample around 500K is likely to neucleate some erysta.lline phases giving rise to ferromagnetism.