High-resolution electron microscopy study of Ni81Fe19 film with Co33Cr67 buffer layer

The anisotropic magnetoresistance (AMR) in permalloy Ni81Fe19 film deposited on a 1.2 nm Co33Cr67 buffer layer was significantly enhanced. The high-resolution electron microscopy was used to study the microstructure of Ni81Fe19 film with and without Co33Cr67 buffer layer. It was found that Co33Cr67 buffer layer can induce good (1 1 1) texture, while without Co33Cr67 buffer layer, Ni81Fe19 film show randomly oriented grain structure. The Δρ/ρ enhancement is attributed to the decrease in the resistivity ρ of the Ni81Fe19 film due to the formation of the large (1 1 1) textured grains in Ni81Fe19 film with Co33Cr67 buffer layer. However, the surface roughness of substrate may limit the (1 1 1) textured grain size and induce additional grain boundaries in Ni81Fe19 film with Co33Cr67 buffer layer, limit the enhancement of the AMR effect