Weak dependence of phase fraction and dopant concentration in \{beta}, α phase mixture of W
Dopant concentration and $α$, $β$ phase fraction is studied in doped W thin films. Oxygen doped $β$ W films are found to have 9.0~$\pm$~0.9 at.\% of oxygen as measured from \ac{SIMS}. Whereas, nitrogen doped $β$ W films have 0.15~$\pm$~0.02 at.\% of nitrogen, much lower than the theoretically predicted value of 11 at.\%. $β$-W films partially phase transform to $α$ by annealing at 175~$^{\circ}$C, up to maximum time of 72 hours. Weak dependence between dopant concentration and phase fraction is observed in the annealed films. The growth exponent of the phase transformation was calculated to be $<$1 in both the films, indicating a non-uniform nucleation of the $α$ phase.
cond-mat.mtrl-sci↗