  Dual-phase Zr-based thin films synthesized by magnetron co-sputtering and
showing competitive growth between amorphous and crystalline phases have been
reported recently. In such films, the amorphous phase grows as columns, while
the crystalline phase grows as separated cone-shaped crystalline regions made
of smaller crystallites. In this paper, we investigate this phenomenon and
propose a model for the development of the crystalline regions during thin film
growth. We evidence using X-ray diffraction (XRD), scanning electron microscopy
(SEM) and transmission electron microscopy (TEM), that this competitive
selfseparation also exists in co-sputtered Zr-Cr thin films with Cr contents of
~84-86 at.%, corresponding to the transition between the amorphous and
crystalline compositions, and in the Zr-V system. Then, to assess the
sturdiness of this phenomenon, its existence and geometrical characteristics
are evaluated when varying the film composition and the deposition rate. The
variation of geometrical features, such as the crystalline cone angle, the size
and density of crystallites, is discussed. Is it shown that a variation in the
deposition rate changes the nucleation and growth kinetics of the crystallites.
The surface coverage by the crystalline phase at a given thickness is also
calculated for each deposition rate. Moreover, comparison is made between
Zr-Cr, Zr-V, Zr-Mo and Zr-W dual-phase thin films to compare their nucleation
and growth kinetics.
