High magnetoresistance permalloy films deposited on a thin NiFeCr or NiCr underlayer

Significantly enhanced anisotropic magnetoresistance (MR) in permalloy (Ni0.81Fe0.19) films deposited on a thin (Ni0.81Fe0.19)(1-x)Cr-x or Ni1-xCrx underlayer is reported. The maximum Delta R/R enhancement was observed using the underlayer with x approximate to 0.44 at an optimum thickness of approximate to 30-45 Angstrom, depending on the deposition technique. An enhancement of 75%-150% was observed for 45-430 Angstrom thick permalloy films, compared to the films deposited without this underlayer. The Delta R/R enhancement is attributed to the decrease in the resistivity rho and the increase in Delta rho of the permalloy film due to the formation of large (111) textured crystal grains in the permalloy films deposited on this underlayer, as revealed by the x-ray diffraction results obtained using synchrotron radiation. (C) 2000 American Institute of Physics. [S0021-8979(00)44308-2].