High magnetoresistance in sputtered permalloy thin films through growth on seed layers of (Ni0.81Fe0.19)(1-x)Cr-x

The use of a thin (Ni0.81Fe0.19)(1-x)Cr-x seed layer for obtaining high anisotropic magnetoresistance in Permalloy (Ni0.81Fe0.19) films is reported. The process yields a high Delta R/R of, for example, 3.2% for 120-Angstrom-thick NiFe, without high-temperature deposition or annealing, X-ray diffraction shows that the NiFeCr seed layer causes the formation of large (111) textured grains in the Permalloy film, and that the interface between these two layers is quite smooth, These both increase the Delta R and reduce the resistance R in the film, which lead to the high Delta R/R, Also discussed is the enhanced Delta R/R and thermal stability trilayer magnetoresistive sensors using this NiFeCr instead of Ta as a spacer.