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conferenceseries
.com
Volume 4, Issue 4 (Suppl)
J Laser Opt Photonics, an open access journal
ISSN: 2469-410X
Optics 2017
November 15-17, 2017
November 15-17, 2017 | Las Vegas, USA
8
th
International Conference and Exhibition on
Lasers, Optics & Photonics
Synthesis and structural characterization of the hexagonal anti-perovskite Na
2
CaVO
4
F
Robert L Green
Florida Polytechnic University, USA
A
high-resolution neutron powder diffraction technique was used to observe and refine the structural details of the ordered
hexagonal oxyfluoride Na
2
CaVO
4
F. Polycrystalline samples were prepared via solid-state synthesis using stoichiometric amounts
of high pure starting materials. The structural changes between 25°C and 750°C revealed that the two structural subunits contained
within this material exhibit different behavior when heated. There is an expansion of the face-shared FNa
4
Ca
2
octahedra while the
VO
4
tetrahedra due to increased thermal disorder reveal marginal bond contractions. The bond valence method is employed to
compare observed and ideal bond distances and point to a structural instability at 750
o
C. The Echidna high-resolution powder
diffractometer located at the OPAL Research Reactor of the Australian Nuclear Science and Technology Organization (ANSTO) was
used for both room temperature and temperature-dependent studies whereby diffraction data was collected using a neutron beam
with a wavelength of 1.6215(1) Å using a Ge (335) monochromator. All preliminary structural information was collected using a
benchtop X-ray diffractometer using Cu-Kα (1.54059 Å) over the range of 3-149° 2-theta. Both X-ray and neutron diffraction data
was refined using the GSAS suite of programs.
Biography
Robert L Green has earned his BS from Morehouse College, an MS from Purdue University and his PhD from the University of South Carolina in Chemistry. For the majority
of his 12 years career in higher education, he has devoted time to promoting STEM education to both K-12 teachers and students underserved communities. He is a Mem-
ber of the American Chemical Society and is the Founder of the Florida Polytechnic University Chapter of the National Society of Black Engineers (NSBE).
rgreen@floridapoly.eduRobert L Green, J Laser Opt Photonics 2017, 4:4 (Suppl)
DOI: 10.4172/2469-410X-C1-017