THIN-FILM STRUCTURES FOR LOW-FIELD GRANULAR GIANT MAGNETORESISTANCE

Giant magnetoresistance (GMR) is a relatively new field of study pursu ed by scientists and technologists alike. A potential application of G MR thin films is the replacement of NiFe alloy thin films (having anis otropic magnetoresistance) to obtain greater signal. Applications of t his type require that the GMR be obtained at low fields, on the order of 10 Oe. In this paper three types of granular GMR thin film structur es are described: codeposited heterogeneous alloys, granular bi-layers , and discontinuous multilayers. Experimental examples of each type ar e presented, and the field dependence of GMR for each structure is dis cussed. Only discontinuous multilayer thin film structures have shown suitable GMR at low fields, and the properties and microstructure of t hese thin films will be described in greater detail.