Co/Cu multilayers were electrodeposited on brass substrates in a single electrolyte, and their magnetic properties were measured using a vibrating sample magnetometer. Samples with various nanometric layer thicknesses down to 0.2 nm were prepared using a coulomb controller and the relationship between the individual layer thickness and the magnetic properties was investigated. All samples showed in-plane magnetic anisotropy. The maximum coercivity value was obtained when the layer thickness was around 0.5-4 nm, and was almost five times higher than that for thick Co single-layer films. The saturation magnetic moment was strongly related to the Co content of the samples. However, for layer thicknesses of less than 10 nm, the Co content was smaller than that predicted by Faraday's law. Moreover, from a quantitative analysis of the samples, it was found that the mass magnetization of Co in the multilayers decreased as the layers became thinner. The highest squareness ratio of almost 0.9 was exhibited for a layer thickness of around 100 nm. Finally, out-of-plane hysteresis measurements revealed that the magnetic moment became more easily saturated as the layers became thinner.
The boron-doped diamond electrode with carrier density of 5.5×1019/cm3 showed high electrochemical response to methylene blue in aqueous solution. The cathodic and anodic current peaks due to leuco-methylene blue / methylene blue redox system were observed clearly on the diamond electrode in the solution containing methylene blue with lower concentration than 10 μM. It was also possible to detect methylene blue in the coexistence of another dye, brilliant blue FCF by using diamond electrode.