Investigations into the Laser Ablation Process and the Pursuit of New Chemical Applications

W. Lester S.弗吉尼亚大学的安德鲁斯得到了 实验物理化学计划，以继续他的矩阵隔离 傅里叶变换红外光谱研究活性物种。 前几 工作，激光烧蚀被用来产生热原子，随后 在基质处或附近反应以形成感兴趣的物质。 在这 奖项，重点是a）了解激光烧蚀过程 B）寻求新的化学应用。 在前一种情况下， 例如，在一个实施例中，PI将调查激活能的来源， 激光烧蚀Fe与O2反应形成OFeO的反应， 不发生热反应。 活化能是由于 过量动能，涉及可吸收材料的电子激发，或 激光等离子体的辐射 对仪器的增加， 磁场或电场将允许操纵带电物质， 这将有助于我们理解 机制等 铍和氧的激光烧蚀实验 氖矩阵将进行，试图分离第一个 中性氖化合物NeBeO 最后，反应的分离 将尝试半导体生长工艺中的中间体。 给定 脉冲激光烧蚀生长半导体薄膜的研究现状 薄膜，GaAs，GaP和InSb与H2的反应将被强调。 密度泛函理论研究将与 Bauschlicher，虽然这个建议的重点是 实验方面。 脉冲激光烧蚀正迅速成为一种极其重要的物理 技术，并且目前用于诸如等离子体 物理学、分析化学和超导体的生长。 更好 了解激光烧蚀过程将有助于进一步促进 这项技术的应用。

W. Lester S. Andrews of the University of Virginia is supported by the Experimental Physical Chemistry Program to continue his matrix-isolation Fourier Transform Infrared studies of reactive species. In previous work, laser ablation was used to generate hot atoms which subsequently reacted at or near the matrix to form the species of interest. In this award, the emphasis is on a) understanding the laser ablation process itself and b) pursuing new chemical applications. In the former case, e.g., the PI will investigate the source for the activation energy of the reaction in which laser ablated Fe reacts with O2 to form OFeO, a reaction that does not occur thermally. Is the activation energy due to excess kinetic energy, electronic excitation involving metastables or radiation from the laser plasma? Additions to the apparatus involving magnetic or electric fields will allow manipulation of charged species, which should lead to an understanding of some of the underlying mechanisms. Laser ablation experiments with beryllium and oxygen in a neon matrix will be carried out in an attempt to isolate the first neutral neon compound NeBeO. Finally, the isolation of reaction intermediates in semiconductor growth processes will be attempted. Given current interest in pulsed laser ablation to grow semiconductor thin films, reactions of GaAs, GaP and InSb with H2 will be emphasized. Density functional theoretical studies will be done in collaboration with Bauschlicher, although the emphasis in this proposal is on the experimental aspects. Pulsed-laser ablation is rapidly becoming an extremely important physical technique and is currently employed in such diverse areas as plasma physics, analytical chemistry and the growth of superconductors. Better understanding of the laser ablation process would help foster further applications of this technology.