Dynamics and Kinetics of Pulsed Laser Deposition: Time-Resolved Synchrotron X-ray Studies

非技术摘要本项目将使用时间分辨的X射线技术来表征通过脉冲激光沉积(PLD)生长薄膜的原子尺度过程。由于材料的原子性，要获得最终的器件性能，预计需要在表面和界面的准备过程中达到原子级的精度。氧化膜的性质对氧含量非常敏感。例如，氧气浓度的小幅增加会将钛酸锶薄膜从绝缘体转变为半导体，然后转变为金属。发展控制和限制氧空位的能力仍然是实现氧化物电子器件全部潜力的重要障碍。该项目将开发和探索一种新的技术(时间分辨漫反射x射线散射)来表征制备过程中此类薄膜中的氧空位。该项目将为研究生和博士后研究助理提供先进的同步加速器X射线技术和PLD生长复合氧化物薄膜方面的强化培训。PI将继续与中小学教师合作开发实践模块，以满足纽约州强制要求的物理课程的目标，并在在职教师培训活动中传播这些材料。技术摘要该项目将使用时间分辨的、基于同步加速器的硬X射线(10keV)技术来表征通过脉冲激光沉积(PLD)生长薄膜的原子尺度过程。本项目将探索利用点缺陷的长程应变场的扩散X射线散射(黄散射)来表征PLD沉积的SrTiO_3薄膜中氧空位的浓度、空间分布、对称性和预期的聚集的可能性。与对原子或分子浓度敏感的光谱技术不同，漫反射x射线散射对空位浓度直接敏感。该项目将为研究生和博士后研究助理提供先进的同步加速器X射线技术和PLD生长复合氧化物薄膜方面的强化培训。PI将继续与小学和中学教师合作，开发实践模块，以满足纽约州强制物理课程的目标，并在在职教师培训活动中传播这些材料。

Non-Technical AbstractThis project will use time-resolved, x-ray techniques to characterize the atomic scale processes governing the growth of thin-films via pulsed laser deposition (PLD). Due to the atomic nature of materials, attaining the ultimate in device performance is expected to require atomic-level precision in the preparation of surfaces and interfaces. The properties of oxide films are very sensitive to oxygen content. For example, a small increase in oxygen concentration changes strontium titanate films from an insulator into a semiconductor and then into a metal. Developing the ability to control and confine oxygen vacancies remains an important barrier to realizing the full potential of oxide electronic devices. This project will develop and explore the potential of a new technique (time-resolved diffuse x-ray scattering) to characterize oxygen vacancies in such films during their preparation. This project will support intensive training in advanced synchrotron-based x-ray techniques and in the growth of complex oxide thin-films by PLD to a graduate student and a post-doctoral research associate. The PI will continue to work with elementary and middle school teachers on projects developing hands-on modules tailored to meet the goals of the NY state mandated physics curriculum and to disseminate these materials at in-service teacher training events.Technical AbstractThis project will use time-resolved, synchrotron-based, hard x-ray (10 KeV) techniques to characterize the atomic scale processes governing the growth of thin-films via pulsed laser deposition (PLD). This project will explore the potential of using the diffuse x-ray scattering from the long-range strain fields of point defects (Huang scattering) to characterize the concentration, spatial distribution, symmetry, and anticipated clustering of oxygen vacancies in SrTiO3 films deposited via PLD. In contrast to spectroscopic techniques which are sensitive to the concentration of atoms or molecules, diffuse x-ray scattering is directly sensitive to the vacancy concentration. This project will support intensive training in advanced synchrotron-based x-ray techniques and in the growth of complex oxide thin-films by PLD to a graduate student and a post-doctoral research associate. The PI will continue to work with elementary and middle school teachers on projects developing hands-on modules tailored to meet the goals of the NY state mandated physics curriculum and to disseminate these materials at in-service teacher training events.