Measurement of magnetic parameters of nanometer-thick conducting magnetic films using anisotropic magnetoresistive effect

Abstract

The angular dependences of anisotropic magnetoresistance (AMR) are measured in conducting ferromagnetic films of nanometer thickness and layered structures containing such films and having the shape of narrow ribbons. These structures are used for preparing spin-dependent magnetic tunnel junctions possessing a giant magnetoresistance. The possibility of determining the main magnetic parameters, which are important for preparing magnetic junctions, by AMR angular measurements is demonstrated experimentally. The magnetic anisotropy axis, the saturating magnetic field, and the coercivity are determined in a 25-nm-thick permalloy (Py) film, in the structures FeMn film (15 nm)-Py film (10 nm) deposited by RF magnetron sputtering on a oxidized silicon substrate, as well as in the structure FeMn (15 nm)-Py (10 nm)-SiC (1.5 nm)-Py (10 nm) deposited on a sitall substrate. It is shown that, under the same conditions of Py films deposition, the magnetic anisotropy axis in the FeMn-Py structure is turned through 90° relative to the anisotropy axis of Py in structures without FeMn layers. The value of the exchange bias fields of the magnetization reversal measured in the structure FeMn (15 nm)-Py (10 nm)-SiC (1.5 nm)-Py (10 nm) by the AMR method is in good agreement with the result of measurement by the inductive method.