Spintronics is certainly one of the most rapidly expanding fields in basic research as well as in industrial application. Magnetic multilayers are the key configurations in this field which allow the utilization of unique magnetic and magnetoresistive phenomena that cannot be realized on the basis of conventional materials. Particularly, Giant Magnetoresistance (GMR) thin films and multilayers are being used in a variety of applications such as magnetic field sensors, hard disc read heads, magnetic random access memory, etc.
       At IITB, nanocrystalline Fe-Cu thin films and antiferromagnetically coupled Fe/Cu multilayers are being investigated. The samples are prepared by using a multi-target dc magnetron sputtering. Structural, microstructural, magnetic and magnetoresistive properties are studied. Magnetoresistance is a very important property that is being investigated systematically by varying the composition and deposition conditions. In this proposal, we will investigate the antiferromagnetically coupled multilayers and films that exhibit giant magnetoresistance. These multilayers are thin stacks of sequentially deposited ferromagnetic and nonmagnetic layers. The magnetic layer will be FeNi and the nonmagnetic layer will be Cu or Ag. The thickness of the individual layers in these multilayers is in the range 1 ? 5 nm. Studies will also be carried out on FeNi based nanocrystalline single films as well. Structural, interfacial, microstructural, magnetic and magnetoresistive properties will be systematically studied by varying the thickness of the layers and deposition conditions. Finally, all the results obtained will be correlated to understand the behaviour of the proposed magnetoresistive multilayers. To carry out these studies, a low temperature magnetoresistance facility is very essential.