Synthesis of Novel Oxyhalides as Multifunctional Host Structures

Professor Rob Green from Alabama State University will present a seminar.

Synthesis of Novel Oxyhalides as Multifunctional Host Structures

Abstract:

A tetragonal oxyfluoride Ba2SrGaO4F, a novel material in the Sr3AlO4F family of materials, has been synthesized via solid-state method and exhibits self-activated photoluminescence (PL) under 254nm light after annealing in a reducing atmosphere of 4%H2/96% Ar. The structure of this material is determined by powder x-ray diffraction and confirmed using high-resolution neutron powder diffraction, which reveals similarities to Sr3AlO4F-type oxyfluorides and Ba2GaLaO5. Analysis of the refined Ba2SrGaO4F structure at room temperature reveals subtle changes in the polyhedral sub-units between the reductively annealed and air-annealed samples, which are correlated with the PL emission.

Biography:

Dr. Robert L. Green is a native of Johns Island, South Carolina. He has earned a B.S. from Morehouse College, an M.S. from Purdue University and his Ph.D. from the University of South Carolina in chemistry. Dr. Green is currently an Associate Professor of Chemistry and Chair of the Department of Physical Sciences at Alabama State University. His current research efforts involve the synthesis and characterization of novel substituted oxide and oxy-halide materials. The core of this research is to study the structure and luminescent properties in phosphor materials in a variety of anti-perovskite host materials. Dr. Green has extensive experience working with undergraduate student researchers. Additionally, he participated and coordinated outreach efforts with K-12 educators for the Richland One and Richland Two School Districts in Columbia, South Carolina to incorporate technology into the curriculum and to provide fun and safe laboratory experiences for K-12 students. He has also participated in other K-12 educator and student outreach programs in Florida for Lake, Sumter, Hillsborough, and Polk County (FL) students.

Host: Dr. Jared Allred