STRUCTURAL, MAGNETOTRANSPORT, AND OPTICAL-PROPERTIES OF SPUTTERED CO CU MULTILAYERS EXAMINED AS A FUNCTION OF CO LAYER THICKNESS AT THE 2NDANTIFERROMAGNETIC MAXIMUM/

A series of {[Co(t(Co))/Cu(2.1 nm)](30)/Co(t(Co))}(30) multilayers hav e been deposited under specific magnetron sputtering deposition condit ions that lead to giant magnetoresistance (GMR) curves with technologi cal interest. X-ray reflectivity, magnetic, magneto-transport, and spe ctroscopic ellipsometry measurements were used together to examine the dependence of their properties upon the Co layer thickness (t(Co)) Re markably, the obtained film density and roughness, the saturation and coercivity fields, the reduced remnant magnetization, the GMR ratios, and the plasma frequency exhibit a significant divergence as a functio n of t(Co) in the range between 1.3-1.6 nm. The observed microstructur al, magneto-transport, and magnetic relative differences, induced in ( 111) textured Co/Cu multilayers by varying the t(Co), were correlated with changes of the optical electronic states of the constituents in t he electronic density of states near the Fermi level. (C) 1998 America n Institute of Physics. [S0021-8979(98)02512-2].