Raman Scattering of Solid and Liquid Clusters and Ultrathin Films

固体和液体团簇以及超薄膜的拉曼散射

• 批准号: 9224165
• 负责人: Jeffrey Lannin
• 金额: $ 28.5万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-05-01 至 1996-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9224165&HistoricalAwards=false
• 关键词: Raman; Scattering; Solid; Liquid; Clusters

Enhanced Raman scattering methods will be used for in situ ultra- high vacuum studies of clusters and ultra-thin films deposited on surfaces. Information about the phonon states and their changes with cluster size and temperature will be obtained. Emphasis will be places on the semiconducting and semimetallic group IV (C and Sn) and V (Bi and Sb) elements in amorphous or nanocrystalline states. Raman scattering will also be applied to liquid clusters from this group to obtain dynamical information on the phase transformations from the solid to liquid state. Sputtering and laser assisted deposition methods will be employed for cluster and ultra-thin film growth. Photoemission and high resolution electron energy loss methods will provide complementary information on changes in electronic and vibrational states and the role of atomic hydrogen bonding on surfaces. %%% This research will focus on both near surface and bulk properties of ulrathin and thin films with different nanostructures. Emphasis will be placed on studies of semiconductor or semimetal cluster structures in which both the relatively small number of atoms and the large surface to volume ratio allow modified material properties to be achieved. Both solid as well as liquid state cluster properties will be explored. The preparation of these materials will employ a diverse range of ultrahigh vacuum deposition methods, including magnetron sputtering, evaporation and laser assisted deposition. The physical properties and characterization of these materials will employ a range of in situ ultrahigh vacuum spectroscopic methods. This will provide information on the electronic state and vibrational dynamics of disordered amorphous and nanocrystalline solids and will explore the role of bonding and structural disorder changes in the processing of ultrathin films. Additional ex situ transmission electron microscopy studies of cluster size distributions will be obtained and related to synthesis methods. Laser assisted deposition of amorphous carbon and other diamond-like materials will involve university-industry collaborations.

增强的拉曼散射方法将用于原位超 团簇和超薄膜的高真空研究 表面。 关于声子态及其变化的信息 将获得团簇尺寸和温度。 重点将 位于半导体和半金属IV族（C和 Sn）和V（Bi和Sb）元素在非晶或纳米晶中 states. 拉曼散射也将应用于液体团簇 以获得关于相位的动态信息 从固态到液态的转变。 溅射和 激光辅助沉积方法将用于簇， 超薄薄膜生长 光电发射和高分辨电子 能量损失方法将提供补充信息， 电子和振动状态的变化以及原子的作用 表面的氢键。 %%% 这项研究将集中在近表面和散装性质 具有不同纳米结构的超薄和薄膜。 重点 半导体或半金属团簇的研究 在这种结构中，原子数量相对较少， 大表面与体积比允许改性材料 要实现的属性。 无论是固态还是液态 将探索集群属性。 制备这些 材料将采用各种不同的真空 沉积方法，包括磁控溅射、蒸发和 激光辅助沉积 物理性能及 这些材料的表征将采用一系列原位 真空光谱法。 这将提供 的电子态和振动动力学的信息 无序的非晶和纳米晶固体，并将探索 键合和结构无序的作用在 处理胶片。 额外的异地传输 团簇尺寸分布的电子显微镜研究将是 获得并涉及合成方法。 激光辅助 无定形碳和其它类金刚石材料的沉积 将涉及大学和产业的合作。