Amorphous films of Formula (Formula and 0.64) prepared by sputtering, melt quenching, or ion irradiation were annealed up to Formula. The crystallized films consist of stoichiometric GeTe and precipitates of the excess element. The laser and ion irradiated Te-rich amorphous alloy exhibits higher stability with respect to the sputtered film, and an enhancement of the relative abundance of edge-sharing Formula tetrahedra at the expense of Ge-rich tetrahedra occurs with respect to the as-deposited amorphous layers. The crystallization temperature increases with the density of Ge–Te bonds because this local rearrangement delays Te precipitation and the subsequent GeTe crystallization. Irradiation does not affect the stability of the Ge-rich alloy in which crystallization is limited by Ge mobility, and the induced local rearrangements are probably prevented by the low atomic diffusivity.
The Electrochemical Society
1 Sep 2010
Volume: 13 Issue: 9 Pages: H317-H320
Electrochemical and Solid-State Letters