Angular dependence of magnetoresistance in bilayer NiFe NiO

The MR ratio was measured as a function of magnetizing angle, theta in bila yer NiO (300 Angstrom)/NiFe(x)x = 50, 100 and 300 Angstrom. The profile of MR ratio, a typical behaviour of two positive peaks at theta - 0 degrees, c hanged to the asymmetric profile with negative MR for theta greater than or equal to 30 degrees, and nearly symmetric with respect to zero field at th eta = 90 degrees. The MR ratio increased with theta and remained constant f or theta greater than or equal to 40 degrees. The MR ratio profile and thei r variations with theta are in good agreement with the calculated ones usin g single-domain model, showing that the crystalline anisotropy contributes significantly to the MR characteristics. (C) 1999 Elsevier Science B.V. All rights reserved.