MAGNETORESISTANCE AND MAGNETIZATION OF FE CR(001) SUPERLATTICES WITH NONCOLLINEAR MAGNETIC-ORDERING/

We study the magnetization and magnetoresistance of superlattices with biquadratic exchange. The equilibrium states are analyzed on the base of the free energy expression that includes all terms up to the fourt h order in components of magnetizations of magnetic sublattices. The c on-elation between the magnetization curve and the magnetoresistance f or various orientation of magnetic field relative to the film plane is established. The experimental studies are made on the samples of mole cular-beam epitaxy grown Fe/Cr superlattices. The positive magnetoresi stance was found for the perpendicular-to-plane magnetic field. It is shown that this effect as well as the characteristic features of the m agnetization curves are connected with the noncollinear magnetic align ment, which exists in our samples, and the fourth order magnetic aniso tropy of unfamiliar type.