IR Spectroscopic Study of Interatomic Interaction in [(CoFeB)₆₀C₄₀/SiO₂]₂₀₀ and [(CoFeB)₃₄(SiO₂)₆₆/C]₄₆ Multilayer Nanostructures with Metal-Containing Composite Layers

This paper presents an IR spectroscopic study of chemical bonds between components of amorphous [(CoFeB)₆₀C₄₀/SiO₂]₂₀₀ and [(CoFeB)₃₄(SiO₂)₆₆/C]₄₆ multilayer nanostructures (MNS's) made up of metal-containing composite layers and different interlayers, which influence their electromagnetic properties. Our results demonstrate that, even though the MNS's have identical elemental compositions, their IR spectra differ significantly. The reason for this is that the main contribution to the IR spectrum of the [(CoFeB)₆₀C₄₀/SiO₂]₂₀₀ MNS is made by its SiO₂ interlayers. The formation of other bonds with oxygen and silicon is blocked by the carbon present in the (CoFeB)₆₀C₄₀ composite layers, as evidenced by the presence of the strongest mode in the IR spectra of this structure, which corresponds to boron carbide, BC. The considerable intensity redistribution to the low-frequency region in the IR spectrum of the [(CoFeB)₃₄(SiO₂)₆₆/C]₄₆ MNS, containing carbon interlayers, is due to the incorporation of nominal SiO2 into the metal-containing composite layers and the partial redistribution of oxygen bonds from the SiO₂ to the 3d transition metals, resulting in the formation of metal oxides and a silicon suboxide. The interaction of the carbon present in the interlayers between the composite layers with elements of the composite layers, in particular with boron, is considerably weaker in comparison with the other MNS, [(CoFeB)₆₀C₄₀/SiO₂]₂₀₀, which has oxide interlayers.