TY - JOUR
T1 - -Phase of Pb on Ge(111)
T2 - The competing roles of electronic bonding and thermal fluctuations
AU - Ancilotto, F.
AU - Selloni, Annabella
AU - Car, Roberto
PY - 1993
Y1 - 1993
N2 - We have studied the low temperature phases of Pb/Ge(111) at Pb coverages =1/3, 1, and 4/3 using ab initio molecular dynamics. Stable phases are found to occur at =1/3 and 4/3. For the low-coverage (=1/3) phase, we confirm the model of Pb atoms adsorbed at T4 sites of the Ge(111) substrate. For the high coverage (=4/3) phase and very low temperature, we determine a structure characterized by the presence of covalently bonded Pb chains parallel to 110 substrate directions. At room temperature, fluctuations are found to disrupt long-range Pb chains and restore the threefold symmetry of the ideal Ge(111) surface. The calculated structure factors and local density of states agree well with x-ray diffraction and STM data.
AB - We have studied the low temperature phases of Pb/Ge(111) at Pb coverages =1/3, 1, and 4/3 using ab initio molecular dynamics. Stable phases are found to occur at =1/3 and 4/3. For the low-coverage (=1/3) phase, we confirm the model of Pb atoms adsorbed at T4 sites of the Ge(111) substrate. For the high coverage (=4/3) phase and very low temperature, we determine a structure characterized by the presence of covalently bonded Pb chains parallel to 110 substrate directions. At room temperature, fluctuations are found to disrupt long-range Pb chains and restore the threefold symmetry of the ideal Ge(111) surface. The calculated structure factors and local density of states agree well with x-ray diffraction and STM data.
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U2 - 10.1103/PhysRevLett.71.3685
DO - 10.1103/PhysRevLett.71.3685
M3 - Article
C2 - 10055046
AN - SCOPUS:4244047957
SN - 0031-9007
VL - 71
SP - 3685
EP - 3688
JO - Physical review letters
JF - Physical review letters
IS - 22
ER -