Based on high purity constituents ternary AlFeSi intermetallic phases were prepared and annealed at 600°C for a month with compositions close to that of αH-AlFeSi (Al8Fe2Si) phase (∼8 wt.% Si, ∼32 wt.% Fe). The powder diffraction patterns and the chemical compositions of the different αH-AlFeSi intermetallic compounds formed as major components in the samples were investigated by X-ray powder diffraction and electron microprobe analysis, respectively.
A complete powder diffraction pattern is presented for the αH-AlFeSi intermetallic phase with 8 wt.% silicon and 33.5 wt.% iron content formed almost congruently. The refined cell parameters are given as
a = 12.4056 (7) Å
c = 26.236 (2) Å
Comparing the observed intensities with intensities calculated from single crystal data, gave very good agreement.
The lattice parameters of αH-AlFeSi phases with different silicon content were refined by the least-squares method. A contraction of the unit cell caused by the increase of the silicon content in the phase can be observed. Relative changes of the cell dimensions for 1 wt. % increase in silicon are −0.06%, −0.09 % and −0.21 % for the parameters a and c and for the unit cell volume, V, respectively.