U.S.-Hungary Materials Research on Point Defects in Optical Crystals

康涅狄格大学的劳伦斯·A·卡珀斯博士和晶体物理研究实验室的I·福尔德瓦里博士之间的这项美国-匈牙利研究项目的主要目标是，布达佩斯是为了研究非线性光学晶体的缺陷性质。要研究的特定材料包括新的铋氧化物Bi2TeO5的掺杂和非掺杂单晶，以及具有本征发光的其他材料(ZnWO4，Bi4Ge3O12，Bi12GeO20、Bi12SiO20和Bi12TiO20)。单晶将在匈牙利晶体物理研究实验室使用Czochralski技术生长，而晶体表征将在匈牙利大学进行康涅狄格州使用电子顺磁共振进行电子辐照前后，光学和光谱学。实验工作将包括研究点缺陷及其在这些材料中的闪烁、光折变和光致变色过程中的参与。比较不同晶体的结果将有助于我们对这些现象的基本理解。此外，补充性的理论研究将建立在研究人员先前合作对副亚硫酸盐中的缺陷进行团簇建模的结果的基础上，并将这些方法扩展到Bi2TeO5。总体而言，综合结果应该会提高我们对那些具有在光学设备中也有应用潜力的性质的氧化物晶体的了解。这个凝聚态物理项目通过使美国和匈牙利的顶尖专家能够结合互补的人才，并在相互感兴趣和能力很强的领域汇集研究资源，实现了推进科学的计划目标。

The primary objective of this U.S.-Hungary research project between Dr. Lawrence A. Kappers of the University of Connecticut and Dr. I. Foldvari of the Research Laboratory for Crystal Physics, Budapest is to study the defect properties of nonlinear optical crystals. Specific materials to be investigated include doped and undoped single crystals of a new bismuth oxide, Bi2TeO5 as well as other materials that possess an intrinsic luminescence, (ZnWO4, Bi4Ge3O12, Bi12GeO20, Bi12SiO20 and Bi12TiO20). Single crystals will be grown at the Research Laboratory for Crystal Physics in Hungary using the Czochralski technique while crystal characterization will be performed at the University of Connecticut before and after electron irradiation using electron paramagnetic resonance, optical and spectroscopy. The experimental efforts will include studies of point defects and their involvement in scintillation, photorefractive, and photochromic processes in these materials. Comparisons of the results for the different crystals will contribute to our basic understanding of these phenomena. In addition, complementary theoretical studies will build upon results of the researchers' previous collaboration on cluster modeling of defects in paratellurite and will extend those methods to Bi2TeO5. Overall, combined results should improve our knowledge of those oxide crystals with properties that also have a potential for applications in optical devices. This project in condensed matter physics fulfills the program objectives of advancing science by enabling leading experts in the U.S. and Hungary to combine complementary talents and pool research resources in the areas of strong mutual interest and competence.