Effect of Interfacial Roughness Configuration on the Exchange-Bias Field in NiO Based Spin Valves

Two series of NiO-Co-Cu-Co based spin valves with the same nominal structure were grown by the magneton sputtering technique with different deposition parameters. Texture, surface and interfacial microstructures and the magnetic properties have been investigated in detail. X-ray diffraction, grazing incident X-ray reflectivity and transverse X-ray diffuse scattering were combined to analyze the microstructure of the multilayers. The results show that the texture of the multilayers is not a prerequisite factor for an exchange-bias (EB) field in NiO/Co/Cu/Co spin valves. And the EB effect is also independent of the average roughness at the interfaces. Large correlation lengths and two dimensions of the roughness at the interface are more advantageous for the EB effect.