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 un derlayer is reported. The maximum Delta R/R enhancement was observed using the underlayer with x approximate to 0.44 at an optimum thickness of approx imate to 30-45 Angstrom, depending on the deposition technique. An enhancem ent of 75%-150% was observed for 45-430 Angstrom thick permalloy films, com pared to the films deposited without this underlayer. The Delta R/R enhance ment 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) text ured crystal grains in the permalloy films deposited on this underlayer, as revealed by the x-ray diffraction results obtained using synchrotron radia tion. (C) 2000 American Institute of Physics. [S0021-8979(00)44308-2].