Giant Magnetoresistance of Metallic Exchange-Coupled Multilayers and Spin Valves

摘要

The microstructure and the magnetic and magnetotransport properties have been investigated depending on the types of the magnetic and nonmagnetic materials, composition, nanostructure, and regimes of thermomagnetic treatments for two types of metallic nanostructures, namely, magnetic multilayers and spin valves, which exhibit the effect of a giant magnetoresistance (GMR). Magnetosensitive materials that are promising for the applications in microelectronics have been synthesized: CoFe/Cu multilayers with record values of the GMR effect (81%); NiFeCo/Cu multilayers with a sensitivity of 0.5%/Oe; and microobjects prepared on the basis of spin valves, which possess the anhysteretic field dependence of the magnetoresistance and a GMR effect equal to 9%. Special attention is given to the methods of decreasing hysteresis. A comparison of the obtained results with the results for similar types of materials published earlier has been carried out.