  In the present study, we demonstrate the measurement of resistivity tensor
($\rho$) along the magnetic axes of a polycrystalline film of ferromagnetic
permalloy (Py). To this end, conventional Hall-bar and a more recent extended
van der Pauw methods were utilized for determining 2D $\rho$ in the film plane.
The samples were prepared by normal incidence sputter deposition within an
in-situ magnetic field to induce in-plane uniaxial magnetic anisotropy in the
film. Since $\rho$ might be affected by the internal magnetization of the film,
we performed measurements by rotation of a saturating magnetic field in the
film plane. Both methods indicate that the average resistivity is lower along
the easy axis of the film compared to the hard axis. Since X-ray diffraction
results indicated no dominating texture in the film, we concluded that there is
a correlation between uniaxial magnetic axes and principal resistivity axes.
This is an important finding that allows determining the direction of magnetic
anisotropy axes without magnetometry. The results also verify atomic or pair
ordering to be the origin of uniaxial magnetic anisotropy in the Py since
resistivity is sensitive to the level of order in solids. The extended van der
Pauw utilized here can be easily performed on the as-received samples which is
of practical interest.
