Abstract
We formed grating-like patterns of hydrogen adatom density on Cu(111) by using complementary patterns of xenon adatom density as the template. The template was preformed by laser-induced thermal desorption of a Xe monolayer on Cu(111) using the interference pattern of two coherent laser pulses. By following the evolution of hydrogen density gratings on Cu(111) from 153 to 183 K with linear optical diffraction, we found that the diffusion of hydrogen atoms on Cu(111) in this temperature range is the classical over-barrier hopping characterized by an activation energy barrier Ediff = 6.4 Kcal/mol (or 279 meV) and a pre-exponential factor D0 = 2.0 × 10 -3 cm2/s. Based on the potential model proposed by Basdescu and coworkers for hydrogen on Ni(111), the WKB tunneling coefficient between the first vibrational excited states of a hydrogen adatom on Cu(111) is expected to be at least one order of magnitude smaller than that on Ni(111), indicating that the classical over-barrier hopping of hydrogen atoms could directly cross over to under-barrier tunneling between ground states on Cu(111).
| Original language | English (US) |
|---|---|
| Pages (from-to) | 877-883 |
| Number of pages | 7 |
| Journal | Europhysics Letters |
| Volume | 76 |
| Issue number | 5 |
| DOIs | |
| State | Published - Dec 1 2006 |
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Surface diffusion of hydrogen atoms on Cu(111) studied by optical diffraction from hydrogen density patterns formed on removable templates of xenon monolayers. / Fei, Y. Y.; Zhu, X. D.
In: Europhysics Letters, Vol. 76, No. 5, 01.12.2006, p. 877-883.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Surface diffusion of hydrogen atoms on Cu(111) studied by optical diffraction from hydrogen density patterns formed on removable templates of xenon monolayers
AU - Fei, Y. Y.
AU - Zhu, X. D.
PY - 2006/12/1
Y1 - 2006/12/1
N2 - We formed grating-like patterns of hydrogen adatom density on Cu(111) by using complementary patterns of xenon adatom density as the template. The template was preformed by laser-induced thermal desorption of a Xe monolayer on Cu(111) using the interference pattern of two coherent laser pulses. By following the evolution of hydrogen density gratings on Cu(111) from 153 to 183 K with linear optical diffraction, we found that the diffusion of hydrogen atoms on Cu(111) in this temperature range is the classical over-barrier hopping characterized by an activation energy barrier Ediff = 6.4 Kcal/mol (or 279 meV) and a pre-exponential factor D0 = 2.0 × 10 -3 cm2/s. Based on the potential model proposed by Basdescu and coworkers for hydrogen on Ni(111), the WKB tunneling coefficient between the first vibrational excited states of a hydrogen adatom on Cu(111) is expected to be at least one order of magnitude smaller than that on Ni(111), indicating that the classical over-barrier hopping of hydrogen atoms could directly cross over to under-barrier tunneling between ground states on Cu(111).
AB - We formed grating-like patterns of hydrogen adatom density on Cu(111) by using complementary patterns of xenon adatom density as the template. The template was preformed by laser-induced thermal desorption of a Xe monolayer on Cu(111) using the interference pattern of two coherent laser pulses. By following the evolution of hydrogen density gratings on Cu(111) from 153 to 183 K with linear optical diffraction, we found that the diffusion of hydrogen atoms on Cu(111) in this temperature range is the classical over-barrier hopping characterized by an activation energy barrier Ediff = 6.4 Kcal/mol (or 279 meV) and a pre-exponential factor D0 = 2.0 × 10 -3 cm2/s. Based on the potential model proposed by Basdescu and coworkers for hydrogen on Ni(111), the WKB tunneling coefficient between the first vibrational excited states of a hydrogen adatom on Cu(111) is expected to be at least one order of magnitude smaller than that on Ni(111), indicating that the classical over-barrier hopping of hydrogen atoms could directly cross over to under-barrier tunneling between ground states on Cu(111).
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U2 - 10.1209/epl/i2006-10366-3
DO - 10.1209/epl/i2006-10366-3
M3 - Article
VL - 76
SP - 877
EP - 883
JO - Europhysics Letters
JF - Europhysics Letters
SN - 0295-5075
IS - 5
ER -