THICKNESS DEPENDENCE OF THE MAGNETORESISTANCE EFFECT IN RF SPUTTERED THIN PERMALLOY-FILMS

Because of their importance to the development of magnetoresistive recording heads, the thickness dependence of the magnetoresistive properties of thin rf sputtered Permalloy films has been measured in the thickness range from 220 A to 5490 A. It was found that the DELTA rho equals rho // parallel minus rho // PERPEND exhibits an oscillatory dependence on film thickness when saturated in a magnetic field. The resistivity rho and DELTA rho / rho also exhibit tendencies in this regard to a lesser degree. The primary source of this oscillatory thickness dependence is the existence of a quantum size effect modified by the magnetic quantization producing a Landau level spectrum.