Reinvestigation of the first nucleated phase in Nb/Si multilayers

Silicide characterization at alumina–niobium interfaces

“…As discussed by Milanese et al [22], thin-film studies can provide limited amounts of one or more components, phases may form sequentially rather than simultaneously, and interfaces may affect growth and diffusion. The discussion in the literature of the considerations that enter into determining the first phase to nucleate in thin-film structures [9,11,17,18] provides an example of such effects. Nucleation energetics may favor metastable phases [20] or extend the stability field.…”

“…In thin-film studies [17][18][19][20][21], various stable and metastable silicide phases and phase-formation sequences have been found, depending on deposition conditions and subsequent annealing conditions. The silicides found include NbSi 2 [17,18], Nb 5 Si 3 [17][18][19], Nb 3 Si [17][18][19][20], amorphous Nb silicides of varying composition [17,18], and a body-centered orthorhombic Nb 11 Si 4 phase [21]. In thin-film (and other periodic) systems, interpretation can be difficult due to limited amounts of one or more components, phases forming sequentially rather than simultaneously, and the effects of interfaces on growth and diffusion [22].…”