Rare Earth Glasses

National Science Foundation Award 0305202
Richard K. Brow, PI
University of Missouri-Rolla

This project is a multi-disciplinary collaboration between materials researchers at the University of Missouri-Rolla and physicists at the University of North Dakota to process and characterize novel rare earth (RE) containing ultraphosphate glasses that possess interesting optical and magnetic properties. The properties of these glasses have an unusual dependence on composition that involves the coordination environment of the RE3+ ions that modify the phosphate glass network. The research team affiliated with the Ceramic Engineering Department and Graduate Center for Materials Research at Missouri S&T will prepare optically active glasses (including Nd- and Er-phosphate compositions) and glasses with potentially large magnetic susceptibilities (e.g., Dy-phosphate compositions) using techniques to minimize contamination by water and transition metals. Optical characteristics, including absorption spectra, fluorescence spectra and fluorescence lifetimes, will be characterized at Missouri S&T and magnetic properties will be determined by the research team affiliated with the Physics Department at the University of North Dakota. Detailed information about the coordination environments of the RE ions will be collected using x-ray absorption spectroscopy and x-ray and neutron diffraction techniques. These experiments will be performed by members of the UND team in collaboration with students and researchers from Missouri S&T. The goal of these structural studies is to provide a detailed explanation of the compositional-dependence of the macroscopic properties of these glasses, and then to use this information to design other technologically significant compositions.

This multi-disciplinary project will provide a detailed understanding of how the molecular-level structure of rare earth-containing glasses affect macroscopic optical and magnetic properties. This information will be used by scientists and engineers who use such glasses for new sensors, amplifiers and other devices that have both civilian and defense applications. The collaborations among students and researchers at both institutions planned for this project will promote the concept that progress in materials research can be best accomplished by diverse, multi-disciplinary teams.

 

Melting labeled neodymium phosphate glass for neutron diffraction. Vitreous carbon crucible is placed in silica crucible and is heated under argon. Flash melting procedure is used to minimize phosphorus volatilization.
Approximately 1.5g of 18Nd2O3 82P2O5 of (isotope enriched Nd-145) glass was produced for neutron diffraction.
Approximately 2g of 25Nd2O3 85P2O5 of (isotope enriched Nd-145) glass was produced for neutron diffraction.
Loading the GLAD (Glass, Liquid, and Amorphous Diffractometer) sample carousel at the IPNS (Intense Pulsed Neutron Source) at Argonne National Labs.
Close up of GLAD's vanadium sample holders. Each holder holds approximately 1.5g of glass powder.
Carbon coated silica ampoules are used to melt ultra-phosphate glasses.
Various rare earth phosphate glasses batched in vitreous carbon crucibles. 
Preparing dry P2O5 via double sublimation.