Comparison of the magnetoresistance (MR) on two groups of spin-valve multilayers, NiO/NiFe/Cu/NiFe/Cu/NiO and NiO/NiFe/Cu/NiFe/Cu, has been made in order to investigate the possibility of the enhanced specular scattering at NiO/metal interface. No clear difference in MR between the two systems has been found, suggesting that the enhancement of specular scattering at interfaces is not the origin of the large MR. For the field direction almost perpendicular to the plane, we found a sensitive angular dependence of MR along with a large unidirectional anisotropy. To sort out any specific characteristics of the spin-valve system compared to the multilayers, thermoelectric power and Hall effect have been investigated for the first time.

No abstract

The q z -dependent sign of the X-ray charge-magnetic interference diffuse scattering observed from an Fe-Gd multilayer is found to be due to rough internal magnetic interfaces in the Gd layers. The internal magnetic roughness is correlated with the charge roughness of the Fe-Gd interface. Born-approximation calculations using a fractal interface model show that the internal and Fe-Gd interfaces have similar magnetic roughness, as evidenced by the similar in-plane cut-off lengths of chargemagnetic height-height correlation functions.