Characterization of core-shell nanoparticles by small angle neutron scattering
AbstractThe Ni3Si-type nanoparticles dispersed in a mixture of H2O/D2O were characterised by SANS using the contrast variation method. The existence of a core-shell structure
in the nanoparticles with a Ni3Si(Al) core and amorphous SiOx shell is confirmed by the SANS measurements. The nanoparticles
were produced by extracting precipitates from a bulk Ni-13.3Si-2Al ( at.%) alloy using electrochemical phase separation
technique and were pre-characterised by X-ray diffraction and transmission electron microscopy. By comparing the precipitate morphology in the Ni-Si-Al alloy with the extracted
nanoparticles in the SANS measurements, it is clearly established that the precipitates shape and size are unaffected by the
extraction process and that the amorphous shell forms on top of the particle core. However, the present measurement could not confirm or exclude the presence of H atoms in the shell structure.