CAREER: Mechanism for Controlling Ionic Valences in Transition Metal Doped Laser Materials

本项目由国际科学与工程办公室和材料研究部陶瓷项目共同资助。非技术描述：该职业项目对光电材料中缺陷的形成、稳定性和操纵有了基本的了解，以便更有效地合成具有定制性能的高质量激光材料。这一研究方向在新型光学器件的开发中极为重要，但尚未得到充分的追求和理解。这个项目具有变革性，因为它将为利用掺杂剂设计和合成具有新能力和功能的光学和光子材料开辟新的途径。该研究对包括激光加工与制造、激光激发聚变能、激光通信、高能粒子与辐射探测、医学成像等广泛的重要应用具有潜在影响。该项目还制定了一项名为“陶瓷科学合作交流研究与材料”的教育计划，通过交换项目帮助学生获得国外（主要是亚洲国家）的研究经验。这种经历使学生对研究活动有了更全面的认识。技术细节：这个CAREER项目的总体目标是解决与使用非价离子取代来控制激光和光电子材料中掺杂离子的价相关的基本材料科学问题。为了回答这些问题，人们正在深入了解选定材料中阳离子缺陷和离子价的形成、稳定性和操纵。具体来说，这个项目的目的是研究通过控制局部氧化或还原环境来调节掺杂离子的价的机制。局部环境的改变可以产生不同的电子和配位结构，从而改变材料中光学活性离子中心的行为。本项目应用模拟方法研究不同掺杂剂和/或掺杂剂组合的模型，以预测可能的光谱特性。用电子显微镜观察不同材料中掺杂物和空位的分布，确定取代离子的位置；它们是否存在于晶格位置或在晶界处分离。这项工作为设计用于下一代器件（如陶瓷激光器和闪烁探测器）的新型光学材料带来了独特的机会。该项目还包括为学生提供专门的增强教育体验，以培养下一代光学和光子材料工程师。

This project is jointly funded by the Office of International Science and Engineering and the Ceramics Program in the Division of Materials Research.NON-TECHNICAL DESCRIPTION: This CAREER project achieves a fundamental understanding of the formation, stability, and manipulation of defects in optoelectronic materials in order to more effectively synthesize high-quality laser materials with tailored properties. This line of research is extremely important in the development of new optical devices, and has not yet been adequately pursued and understood. This project is transformative, as it will open new avenues for utilizing dopants to design and synthesize optical and photonic materials with new capabilities and functionalities. The research has potential impacts on a wide range of important applications, including laser machining and manufacturing, laser-sparked fusion energy, laser communications, high-energy particle and radiation detection, medical imaging, etc. The project has developed an educational program called Collaborative Exchange Research and Materials in Ceramic Sciences (CERAMICS) to help students gain research experience abroad, primarily in Asian countries, through an exchange program. This experience provides students with a more global view of research activities. TECHNICAL DETAILS: The overall objective of this CAREER project is to address the fundamental materials science questions associated with using off-valence ion substitution to control the valency of dopant ions in laser and optoelectronic materials. To answer these questions, a thorough understanding of the formation, stability, and manipulation of cation defects and ionic valencies in select materials is being developed. Specifically, the intention of this project is to study the mechanisms by which the valencies of dopant ions can be tuned, by controlling the local oxidizing or reducing environment. Modification of local environments can generate different electronic and coordination structures, which changes the behavior of the optically-active ion centers in a material. This project applies simulation methods to study models with different dopants and/or combinations of dopants to predict possible spectroscopic properties. Electron microscopy is used to examine the distribution of dopants and vacancies in different materials, and to determine the location of substitutional ions; whether they exist in lattice sites or are segregated at grain boundaries. This work brings about unique opportunities to design new optical materials for applications in next generation devices such as ceramic lasers and scintillation detectors. The project also includes a dedicated enhanced educational experience for students, which trains future generations of optical and photonic materials engineers.