quartz substrates and annealed under ultra-high vacuum at 500 °C and
600 °C for 1 h at each temperature. Conversion electron Mössbauer
spectroscopy and X-ray diffraction analyses revealed the presence of
both phases of stainless steel: α-phase of body-centered cubic structure
(BCC), and γ-phase of face-centered cubic (FCC). Annealing of 304
stainless steel thin films ensures the α → γ transformation of the structure
and causes reduction of disruption in crystal lattice of α, and the
growth of a newγ-phasewithminimal defects. Crystal sizes of annealed
thin films for α and γ phases are almost identical. The development in
crystal size of both phaseswith annealing could be described by heterogeneous
germination, where the germination rates of α and γ crystals,
are inversely proportional. X-ray diffraction rocking curve method was
used to determine the texture degree of the thin films and it showed
that annealed thin films do not exhibit a preferential orientation of crystals.
The stress of as-grown thin films was found to be independent on
the thin film thickness, and it is equal to +1.12 ± 0.04 GPa in average
as determined by the curvature method. Nevertheless, the stress of
the thin filmswas reduced after annealing to+0.0005 GPa due to relaxation
of the thin films that was caused by reduction of disruption initiated
by self-diffusion of atoms in the crystal lattice. Overall, the
present study introduces a procedure for α → γ phase transformation
of stainless steel thin films, produced by thermal evaporation, that
might be utilized for practical applications including, but not limited
to, medical production, chemical processing, food production, oil and
gas, and power generation.
References