Theoretical studies of dispersion relation of surface phonons in a magnetic field and energy dissipation of adsorbed molecules

磁场中表面声子色散关系及吸附分子能量耗散的理论研究

• 批准号: 09640474
• 负责人: SHIMAMURA Isao
• 金额: $ 2.05万
• 依托单位: RIKEN (The Institute of Physical and Chemical Research)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640474/
• 关键词: Solid Surface; Atomic Collision; Molecule-Surface Collision; Surface Phonon; Surface Phonon Excitation; 表面; イオン・表面衝突; 電荷移行過程; 原子・表面衝突

The main aim in the first year was to understand the process of formation of surface phonons in collisions of a surface with low-energy atoms or ions, and of the decay of the surface phonons. The potential energy surfaces (PES) for the He atom (the HeィイD1+ィエD1 ion) impinging on the Ni (or CU) surface were calculated. The cross section for charge transfer at incident energies E of 10 meV to 1 eV was calculated as a model case and was found to be as large as 10ィイD1-16ィエD1 cmィイD12ィエD1. In the next year, the main objective was the study of the adsorption of molecules on a solid surface and the dissipation of the vibrational excitation energy to the solid. In the molecular collisions at several eV, the translation-vibration interaction and the molecular vibration-surface phonon interaction were the main interactions. There are two kinds of adsorption, "molecular adsorption" in which the molecules do not dissociate, and "dissociative adsorption" in which the molecules dissociate into fragmen … More ts after adsorption. To understand the molecular adsorption mechanism in detail, we used the molecule-surface PES calculated in the first year and the quantum mechanical close-coupling method for the dynamics. The last year was devoted to the study of energy exchange in collisions of HィイD22ィエD2 and OィイD22ィエD2 with Ni, Cu, and Fe surfaces by using a semiclassical simulation method. The parameters we changed are E (0.1-10 eV), rotational-vibrational quantum numbers (v, J), and the surface temperature. The results obtained about the adsorption, energy transfer, and energy dissipation processes are: (I) At E<1 eV, HィイD22ィエD2 in the ground (v, J) state collide with the surface and are adsorbed after hopping on the surface several times. For highly excited (v=5-10, J=10-29) HィイD22ィエD2, they hop more often than for the ground-state HィイD22ィエD2 and can be adsorbed eventually. The energy dissipation occurs after a considerable amount of time after the collision. (ii) At E<1 eV, OィイD22ィエD2 in the ground (v, J) state collide with the surface and are adsorbed after hopping on the surface several times. The number of hopping, however, is less than for HィイD22ィエD2. Some molecules are dissociated depending on their orientation at the time of the collision. The energy dissipation is a slow process in this case too. For surfaces with heavy atoms, the phonon energy sometimes localizes on the surface without dissipation into the second layer or deeper. Less

第一年的主要目标是了解表面声子与低能原子或离子碰撞形成的过程，以及表面声子的衰变过程。计算了He原子（He_xD_1 + He_xD_1离子）碰撞Ni（或Cu）表面的势能面。在入射能量E为10 meV至1 eV的情况下，电荷转移的截面被计算为模型情况，并发现其大至10 μ π ι D1-16 μ π ι D1 cm μ π ι D12 μ π ι D1。在接下来的一年里，主要目标是研究分子在固体表面上的吸附和振动激发能在固体中的耗散。在数eV的分子碰撞中，主要的相互作用是振动-振动相互作用和分子振动-表面声子相互作用。吸附有两种，一种是分子不离解的“分子吸附”，另一种是分子离解成碎片的“离解吸附”。 ...更多信息 TS吸附后。为了详细了解分子吸附机制，我们使用第一年计算的分子表面PES和量子力学紧耦合方法的动力学。过去一年致力于通过使用半经典模拟方法研究H D22 D2和O D22 D2与Ni、Cu和Fe表面碰撞中的能量交换。我们改变的参数是E（0.1-10 eV），转动-振动量子数（v，J）和表面温度。关于吸附、能量转移和能量耗散过程的结果是：（I）在E<1 eV时，基态H D22 D2与表面碰撞，并在表面跳跃几次后被吸附。对于高激发态（v=5-10，J=10-29）H D22 D2，它们比基态H D22 D2跳跃得更频繁，并最终被吸附。能量耗散发生在碰撞后相当长的时间之后。(ii)在E<1 eV时，基态（v，J）的O D22 D2与表面碰撞，并在表面上跳跃几次后被吸附。然而，跳跃的次数少于H D22 D2。一些分子在碰撞时根据它们的取向而解离。在这种情况下，能量耗散也是一个缓慢的过程。对于具有重原子的表面，声子能量有时局限于表面而不耗散到第二层或更深处。少

项目成果

M.Kimura: "Vibrational Excitaiton in Scattering of CO with Ag Surface"Atomic Collision Research in Japan. 25. 72-74 (1999)

M.Kimura：“CO 与 Ag 表面散射中的振动激发”日本原子碰撞研究。

J.-P. Gu: "Charge Transfer Processes in Collisions of H+ Ions with P Atoms at Low Energies"RIKEN Accelerator Progress Report. No.32. 85 (1999)

J.P。

M.Kimura and I.Shimamura: "Vibrational excitation in scattering of CO with Ag surface"Atom.Coll.Research Jpn.. 25. 72-74 (1999)

M.Kimura 和 I.Shimamura：“Ag 表面 CO 散射中的振动激发”Atom.Coll.Research Jpn.. 25. 72-74 (1999)

M. Kimura: "Vibrational Excitation in Scattering of CO with Ag Surface"Atomic Collision Research in Japan. No.25. 72-74 (1999)

M. Kimura：“CO 与 Ag 表面散射中的振动激发”日本原子碰撞研究。

M. Kimura: "Vibrational Excitation in Scattering of CO with Ag Surface"RIKEN Accelerator Progress Report. No.33(in press). (2000)

M. Kimura：“Ag 表面 CO 散射中的振动激发”RIKEN 加速器进展报告。