Impurity Locations and Mechanisms of Charge Compensation in Stoichiometric Lithium Niobate and Lithium Tantalate Crystals

Montana State University, Bozeman MT

Investigators

Abstract

This proposal is on a technologically important class of materials, Lithium Niobate(LN) and Lithium Tantalate (LT), of great potential in electro-optics. These materials are of analogous significance to the electro-optics industry as pure Silicon is to the electronics industry. The project will concentrate on studies of defect structures in single crystals of pure and doped versions of these materials as well as on the mutual influence of intrinsic and extrinsic defects studied through Electron Paramagnetic Resonance (EPR) and Electron Nuclear Double Resonance (ENDOR). Systematic studies will be carried out at Montana State University in a newly purchased Bruker EPR spectrometer. The samples will be obtained from crystal growers worldwide and through a partnership with local company, Scientific Materials, Bozeman, MT. Participation of graduate and undergraduate students including women and members of underrepresented groups will be given priority. This proposal deals with a class of materials that have great potential for applications in electro-optics i.e. the manipulation of light with an electric field. Two materials of relevance in this context, Lithium Niobate and Lithium Tantalate will be studied in their crystalline form. Questions to be addressed include the degree of perfection that these crystals can reach and if they are not perfect what is the nature of the defects in them? These questions will be answered using a resonance technique where the electrons in the material will be excited in a magnetic field. A company close to the investigators' university will be involved in producing the requisite crystals for the study. The principal investigator will emphasize the participation of women and minorities in the project.