High temperature X-ray diffraction study of phase decomposition in rapidlyquenched Al-Ge-Si

The phase decomposition occurring during the heating of rapidly quenched Al -Ge-Si allays has been investigated in situ by means of synchrotron radiati on X-ray diffraction. The metastable Al-Ge phases formed in the as-quenched state transform during heating to Al and Ge. The addition of silicon decre ases the transformation temperature. A Ge(Si) solid solution is indicated b y a systematic change in the lattice constant of Ge as a result of the diff usion of Si From the Al matrix into the phase-separated Ge matrix. (C) 1999 International Centre for Diffraction Data. [S0885-7156(98)01404-3].