Monte Carlo calculations of the magnetoresistance in magnetic multilayer structures with giant magnetoresistance effects

Calculation of CPP-and CIP-magnitoresistance in multilayer magnetic structures

“…We use the Hamiltonian of the anisotropic Heisenberg model [4,5] for the Monte Carlo statistical description of the magnetic properties of Fe films for Fe/Cr(100)/Fe multilayer structure with the out of plane magnetization in Fe films (1) and for Co films in Co/Cu(100)/Co multilayer structure with the in plane magnetization in Co films (2) Therein, J ij characterizes the short-range exchange interaction between the spins Si, fixed at the sites of a body-centered cubic (bcc) lattice for Fe films and facecentered cubic (fcc) lattice for Co films.…”

“…We developed in [4,5] a new methodology for determination of the magnetoresistance (MR) with the use of the Monte Carlo method for measurements of MR with the current perpendicular to plane (CPP -MR). The magnetoresistance had been calculated for three-layer and spin-valve magnetic structures at various thicknesses of ferromagnetic films.…”

Manifestation of aging in giant magnetoresistance of the Co/Cu/Co nanostructure

“…To this effect, the simulated structure was reduced to equilibrium state for times much greater than relaxation time. We have used in papers [25,26] for calculation of the CPP magnetoresistance the two-current Mott model to describe the resistance of different conduction channels [39]. It was introduced the resistance of an ferromagnetic film for two groups of electrons with spins up R ↑ and spin down R ↓ .…”

“…The electron densities with spin up and down can be expressed through the magnetization of the film n n m 1 2 , =    ( ) determined in the process of the Monte Carlo simulation of magnetic properties of the structure. The averaged electron velocity V , á ñ   can be expressed through the electron mobility and the external electric field intensity E, and after that through the probability of electron displacement in unit time (corresponding to one Monte Carlo step per spin) from unit cell i to a neighbouring unit cell in the direction of the electric field with averaging over all film unit cells [25,26].…”

“…This makes it possible to reveal the dependence of aging effects in this structure on thickness N of the magnetic films and temperature T in magnetic-ordered phase. In addition, we plan to calculate the temperature dependence of equilibrium values of the magnetoresistance for Co/Cu/Co structure with different thicknesses N of the magnetic films with the use of the methodology which has been developed in papers [25,26] for determination of the magnetoresistance by the Monte Carlo method. Thereafter, the study of influence of aging effects on the magnetoresistance of Co/Cu/ Co structure is realized and obtained two-time dependences of the magnetoresistance are compared in longtime regime with equilibrium values of the magnetoresistance.…”