An ultrahigh vacuum apparatus for H atom scattering from surfaces

Bünermann, Oliver; Jiang, Hongyan; Dorenkamp, Yvonne; Auerbach, Daniel J.; Wodtke, Alec M.

doi:10.1063/1.5047674

Cited by 26 publications

(32 citation statements)

References 37 publications

(43 reference statements)

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“…The experimental apparatus has been described in detail in Ref. (36). Nearly mono-energetic hydrogen atom beams are generated by photolyzing a supersonic beam of hydrogen iodide with ArF or KrF excimer laser light.…”

Section: Methodsmentioning

confidence: 99%

Imaging covalent bond formation by H atom scattering from graphene

Jiang

Kammler

Ding

et al. 2019

Science

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149

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Viewing the atomic-scale motion and energy dissipation pathways involved in forming a covalent bond is a longstanding challenge for chemistry. We performed scattering experiments of H atoms from graphene and observed a bimodal translational energy loss distribution. Using accurate first-principles dynamics simulations, we show that the quasi-elastic channel involves scattering through the physisorption well where collision sites are near the centers of the six-membered C-rings. The second channel results from transient C–H bond formation, where H atoms lose 1 to 2 electron volts of energy within a 10-femtosecond interaction time. This remarkably rapid form of intramolecular vibrational relaxation results from the C atom’s rehybridization during bond formation and is responsible for an unexpectedly high sticking probability of H on graphene.

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Section: Methodsmentioning

confidence: 99%

Imaging covalent bond formation by H atom scattering from graphene

Jiang

Kammler

Ding

et al. 2019

Science

Self Cite

149

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“…A detailed description of the experimental setup is presented in Ref. 23. In short, a molecular beam of hydrogen halide molecules is formed in a supersonic expansion from a pulsed nozzle.…”

Section: Methodsmentioning

confidence: 99%

Inelastic H and D atom scattering from Au(111) as benchmark for theory

Jiang

Dorenkamp

Krüger

et al. 2019

The Journal of Chemical Physics

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Efficient transfer of translational energy to electron-hole pair excitation involving multiple collisions dominates H atom collisions with metal surfaces. For this reason, H atom interaction with metal surfaces cannot be modeled within the commonly used Born-Oppenheimer approximation (BOA). This fact makes H atom scattering from metal surfaces an ideal model system for dynamics that go beyond the BOA. We chose the H/Au(111) system as a model system to obtain a detailed dataset that can serve as a benchmark for theoretical models developed for describing electronically nonadiabatic processes at metal surfaces. Therefore, we investigate the influence of various experimental parameters on the energy loss in detail including isotopic variant, incidence translational energy, incidence polar and azimuthal angles, and outgoing scattering angles.

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“…Figure 1 shows key components of the apparatus, which has been described in detail elsewhere. 131 The vacuum system consists of a source chamber, two differential pumping stages (DS 1 and DS 2), the main scattering chamber, and a sample preparation chamber (not shown), to which the sample can be moved by translating the manipulator along the + z direction. The source chamber is pumped by a cryopump (COOLVAC 1500 CL-V, Oerlikon Leybold Vacuum GmbH) and houses a pulsed nozzle to generate a supersonic beam of hydrogen halide (HX) molecules (green), which is skimmed (red) and condensed on a LN 2 cooled beam catcher (copper).…”

Section: Experimental Methodsmentioning

confidence: 99%

“…Inspired by work in gas phase chemical dynamics, we have recently developed a new experimental tool to study inelastic H atom scattering from solid surfaces. 131 The apparatus combines Rydberg atom tagging 21 , 23 − 35 with photolytic H atom beams using hydrogen halides as precursors, 300 − 167 in a design that is compatible with ultrahigh vacuum surface scattering. Our new apparatus provides scattering energy and angular distributions with variable incidence energies ranging from 200 meV to 7 eV and energy widths as narrow as 2 meV or even narrower.…”

Section: Introductionmentioning

confidence: 99%

Inelastic Scattering of H Atoms from Surfaces

2021

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We have developed an instrument that uses photolysis of hydrogen halides to produce nearly monoenergetic hydrogen atom beams and Rydberg atom tagging to obtain accurate angle-resolved time-of-flight distributions of atoms scattered from surfaces. The surfaces are prepared under strict ultrahigh vacuum conditions. Data from these experiments can provide excellent benchmarks for theory, from which it is possible to obtain an atomic scale understanding of the underlying dynamical processes governing H atom adsorption. In this way, the mechanism of adsorption on metals is revealed, showing a penetration–resurfacing mechanism that relies on electronic excitation of the metal by the H atom to succeed. Contrasting this, when H atoms collide at graphene surfaces, the dynamics of bond formation involving at least four carbon atoms govern adsorption. Future perspectives of H atom scattering from surfaces are also outlined.

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An ultrahigh vacuum apparatus for H atom scattering from surfaces

Cited by 26 publications

References 37 publications

Imaging covalent bond formation by H atom scattering from graphene

Imaging covalent bond formation by H atom scattering from graphene

Inelastic H and D atom scattering from Au(111) as benchmark for theory

Inelastic Scattering of H Atoms from Surfaces

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