La3/4Sr1/4MnO3/LaNiO3 multilayers: structural and magnetic characterization

M. GRANADA; J. C. ROJAS SÁNCHEZ; L. B. STEREN

Buenos Aires, Argentina

Workshop; Recent developments in complex materials: production and characterization; 2005

Magnetoresistive materials have been extensively studied during the last years due to their potential application in spintronics, i.e. devices in which the charge carriers are spin-polarized. At present, the magnetoresistive heads are based on giant magnetoresistance (GMR) effect, present in ferromagnetic (FM) metal / non-magnetic (NM) metal multilayers. The magnitude of this effect depends on the properties of both the ferromagnetic material and the non-magnetic spacer as well as on the interfaces. We present the structural and magnetic characterization of La3/4Sr1/4MnO3 (LSMO)/ LaNiO3 (LNO) multilayers. LSMO is a FM manganite, with nearly 100% spin polarization of the charge carriers, which makes it an interesting candidate for GMR devices. LNO is a NM metal, with lattice parameter very similar to that of LSMO and the same perovskite structure. We have grown multilayers of these compounds by dc sputtering. X-Ray diffraction patterns show well defined superlattice peaks. Magnetization measurements allow us to determine a LNO thickness for which the LSMO layers are magnetically uncoupled.