Real time study of the growth of i-AlCuFe in very thin films obtained by simultaneous deposition of the components

Kinetics of the crystallization of icosahedral phase in ultra thin deposits of Al62Cu25.5Fe12.5alloy

“…For each experiment, the kinetics of transformation in QC-phase is a function of the sizes of -particles (therefore of the length L) and of the unknown value of (T), when T reaches 723 K. Thus only the shape of the monotonic theoretical kinetic growth is significant. But as previously described [3], for long heat treatment, when the rate should tend to zero, the experimental curves R(t) show a brutal discontinuity. From the observations made by TEM imaging, this second order discontinuity is interpreted as due to a superimposed coalescence kinetics.…”

“…The experimental procedure has been previously described [3]. During annealing, made directly in electron microscope at constant temperatures above 723 K, bright-field TEM images were periodically recorded.…”

“…Deposits made on Ni grids were observed by TEM during different isothermal annealings made at different temperatures T. A previous study has shown that for long annealing made at T <723 K, only -Al 50 (Cu,Fe) 50 crystalline phase and -Al precipitates appeared in the amorphous matrix. Only during annealing above 723 K were the nucleation and growth of i-AlCuFe around the crystallites observed [3]. To optimize the heat treatment in order to obtain quasicrystallization, this study consists in understanding and attempting to describe the growth kinetics during the annealing stage.…”

Formation of α-approximant and quasicrystalline Al–Cu–Fe thin films

“…A piece of the A 1 -sample was monitored with smaller temperature steps from 390 °C to more accurately determine the formation temperature of the α-phase. The α-phase first appeared after 1 h at 430 °C, which is a temperature lower than the formation temperature for the icosahedral ψ-phase mentioned in literature [12,20]. At 570 °C only the ω, with weaker intensities, and α-phases (lattice parameter, a=1.247 nm) are present.…”

Observations on the growth of Al–Ni–Co decagonal thin films by atomic force microscopy and transmission electron microscopy

“…In fact, the production of quasicrystalline films has been attempted by a number of different techniques based on either of these methods. Many of the successful attempts, especially for ternary QC films, were based on the former two methods [6][7][8][9][10][11][12]. Among many deposition techniques, sputtering or laser abration combined with high vacuum pumping system, each of which is capable of minimizing contamination and controlling appropriately the composition of a multicomponent alloy film, seems to be highly effective in producing homogeneous quasicrystalline films such as Al-Cu-Fe [6], Al-Pd-Mn [7,13], Al-Cu-Co [8] and Ti-Ni-Zr [10] alloys.…”