Magneto-optical properties of multilayer nanoheterogeneous structures [(CoFeB)60C40/SiO2]200 and [(CoFeB)$_{34}$(SiO$_2$)$_{66}$/C]$_{46}$

Magnetic properties in two multilayer nanostructures [(CoFeB)$_{60}$C$_{40}$/SiO$_2$]$_{200}$ and [(CoFeB)$_{34}$(SiO$_2$)$_{66}$/C]$_{46}$ with different contents of the CoFeB magnetic alloy in metal-composite layers and an inverted arrangement of nonmetallic phases C and SiO$_2$, in composite layers or in interlayers were investigated by magneto-optical methods. Using the spectral and field dependences of the transverse Kerr effect (TKE), it was found that in both MNSs the magneto-optical response and magnetic order are determined by the composition of the composite layers. In the MNS [(CoFeB)$_{60}$C$_{40}$/SiO$_2$]$_{200}$ with a post-percolation content of metal clusters, the maximum absolute values ​​of the TKE decrease by about 2.5 times in comparison with the pure amorphous CoFeB alloy, while the form of the field dependences of the TKE in this MNS has features characteristic of soft ferromagnets. In another MNS [(CoFeB)$_{34}$(SiO$_2$)$_{66}$/C]$_{46}$ with a pre-percolation content of metal clusters in the SiO$_2$ oxide matrix, the TKE spectral dependences fundamentally differ from the TKE of the initial amorphous CoFeB alloy both in shape and sign. The field dependences of the TKE of this MNS are linear in nature, characteristic of superparamagnets.