TY - JOUR
T1 - Direct imaging of two-state dynamics on the amorphous silicon surface
AU - Ashtekar, S.
AU - Scott, G.
AU - Lyding, J.
AU - Gruebele, M.
PY - 2011/6/10
Y1 - 2011/6/10
N2 - Amorphous silicon is an important material, amidst a debate whether or not it is a glass. We produce amorphous Si surfaces by ion bombardment and vapor growth, and image discrete Si clusters which hop by two-state dynamics at 295K. Independent of surface preparation, these clusters have an average diameter of ∼5 atoms. Given prior results for metallic glasses, we suggest that this cluster size is a universal feature. The hopping activation free energy of 0.93±0.15eV is rather small, in agreement with a previously untested surface glass model. Hydrogenation quenches the two-state dynamics, apparently by increasing surface crystallinity.
AB - Amorphous silicon is an important material, amidst a debate whether or not it is a glass. We produce amorphous Si surfaces by ion bombardment and vapor growth, and image discrete Si clusters which hop by two-state dynamics at 295K. Independent of surface preparation, these clusters have an average diameter of ∼5 atoms. Given prior results for metallic glasses, we suggest that this cluster size is a universal feature. The hopping activation free energy of 0.93±0.15eV is rather small, in agreement with a previously untested surface glass model. Hydrogenation quenches the two-state dynamics, apparently by increasing surface crystallinity.
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U2 - 10.1103/PhysRevLett.106.235501
DO - 10.1103/PhysRevLett.106.235501
M3 - Article
C2 - 21770518
AN - SCOPUS:79960643508
SN - 0031-9007
VL - 106
JO - Physical Review Letters
JF - Physical Review Letters
IS - 23
M1 - 235501
ER -