Neutral-dangling bond depletion in a-SiN films caused by magnetic rare-earth elements

Amorphous silicon-nitrogen thin films doped with rare-earth elements (a-SiN:RE; RE = Y, La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Yb, and Lu) have been prepared by co-sputtering and studied by means of electron spin resonance (ESR). It was found that the neutral dangling-bond density [D0] of a-SiN films decreases with the presence of magnetic REs and the drop of [D0] approximately scales with the spin and/or the de Gennes factor of each rare-earth element. These results suggest that a strong exchange-like interaction, H=J(RE-D0)S(RE).S(D0), between the spin of the magnetic REs and D0 may be responsible for this behaviour, similarly to the decrease of Tc in RE-doped superconductors.