Development of new waterproof thin-layers for the magnetic alloy core. Structural studies using neutron reflectometry

Waterproof thin layers of perhydropolysilazane-derived silica (PDS), and polytetrafluoroethylene (PTFE) were synthesized on silicon substrates. The samples were studied by Fourier-transform infrared (FT-IR) spectroscopy, Xray reflectivity (XR), and neutron reflectivity (NR) analyses. The vibrational modes of functional groups in the synthesized PDS and PTFE thin layers were determined via FT-IR spectroscopy. The density and thickness of the thin layer samples were estimated by NR and XR analyses. The obtained densities and thicknesses were 1.63 g/cm³ and 30 nm for PDS, and 1.47 g/cm³ and 572 nm for PTFE thin layers, respectively. Additionally, NR analysis demonstrated that the water molecules did not penetrate the PTFE layer. These results suggest that the PTFE thin layer is hydrophobic than the PDS thin layer. (author)