Study on N₂-added and B-doped effect in Co/Pd multilayered films using soft x-ray absorption and magnetic circular dichroism

The soft x-ray absorption and magnetic circular dichroism spectra at the Co L_2,3-edges of [Co/Pd]₂₀ and [CoB/Pd]₂₀ multilayered films, which were sputter-deposited in Ar gas containing N ₂ at room temperature, were measured to investigate the electronic and spin states of the films. The macroscopic magnetic properties, such as coercivity and saturation magnetization, and microstructural properties, such as grain size and preferred orientation, were markedly changed for the [Co/Pd]₂₀ film by the B doping and N₂ addition. The B doping and/or the addition of N₂ gas caused appreciable changes not only in macroscopic magnetic properties but also in microscopic properties, such as the spin angular momentum and orbital angular momentum, throughout the multilayered film. On the other hand, a new spectral feature at the high energy side of the Co L₃-edge peak in x-ray absorption spectra was found in only the films with N₂ added. Thus, the microscopic properties, such as electronic and spin states, of the Co 3d electronic state for the [Co/Pd]₂₀ and [CoB/Pd]₂₀ films were changed by only the sputtering process with additive N₂ gas.