High Temperature GMR Multilayers

This SBIR Phase I proposal will demonstrate the feasibility of high temperature giant magnetoresistive (GMR) multilayers. GMR multilayers currently offer the most commercial-ready materials for magentic sensor and memory applications, and NVE has released a line of sensors using these materials. Problems with temperature stability of these multilayer structures, however, limit the applications and impede the commercial success of devices employing this technology. A more stable GMR sandwich material has been substituted in some sensor applications, but these materials are inferior to the multilayer in GMR, linearity, hysteresis, and range of saturation field. The goal of this program is to further develop GMR multilayer materials using the concept of "overdesign," first introduced by Parker, et al, to enhance temperature stability. The objectives of the program are as follows: develop DOE's for material fabrication of multilayers and temperature experimentation using the overdesign concept; process multilayer materials with acceptable magnetoresistive and temperature characteristics; test and characterize GMR multilayers; and develop a model of thermally stable GMR multilayers. Based on the Phase I results, a Phase II program will refine multilayer materials for specific applications and develop and characterize commercially viable sensor and memory devices.