Dissertations and Theses @ UNI
Availability
Open Access Thesis
Keywords
Samarium; Sulfides;
Abstract
The experiments conducted explored lanthanide-arsenic-sulfide ternary systems with particular emphasis on the lanthanide, samarium. A number of stoichiometric mixtures in the samarium arsenic sulfide ternary system were prepared. The samples were sealed into evacuated silica ampoules and then annealed at 900°C. The final products were identified by characterize by X-ray powder diffraction. The powder analyses were used to construct a portion of the ternary phase diagram at 900°C. Every sample contained three common phases, SmAs, AsS and As4S3. Since these compounds were found in every sample, they were not included in the phase diagram. The phase diagram did split into two different parts, arsenic sulfides and samarium sulfides. When the mole percent of arsenic was low, there was a strong tendency to form samarium sulfide binaries with the arsenic being tied up into the three binaries found in all samples, SmAs, As4S3 and AsS. However as the mole percent of arsenic increased, there was increased production of arsenic sulfide binaries. There were a couple of patterns noted for the three common phases to all the samples. The first pattern was that regardless of the starting stoichiometry, the percentage of SmAs in the final product mixture was around 25%. Secondly, the amount of As4S3 was typically less that 15% of the product mixture. The final pattern was that the percentage of total arsenic sulfide phases ranges from 31-42%. These results suggested that arsenic has a greater affinity for sulfur instead if samarium. A salt flux containing 45%/55% by mass of LiCl/RbCl was used to grow single crystals suitable for X-ray diffraction. The crystal structure of SmAsS was investigated using X-ray single crystal diffraction. The compound crystallize in the Pnma space group with the lattice parameters of a= 3.8544, b = 3.9063, c = 17 .1134. A parallel refinement in the reported space group for SmAsS of P21/c was also performed using an unmerged data set. The R factors were nearly identical for the two refinements 0.0658 and 0.0659 for P21/c and Pnma respectively for the isotropic refinement. The final anisotropic refinement using a merged data set of the structure used the Pnma space group. The final Rl/wR2 factors were 0.0365/0.0923for reflections above the þÿ4Ã.
Year of Submission
2002
Degree Name
Master of Science
Department
Department of Chemistry
First Advisor
Laura H. Strauss
Second Advisor
Curtiss D. Hanson
Third Advisor
Paul E. Rider
Date Original
2002
Object Description
1 PDF file (52 leaves)
Copyright
©2002 Chad Michael Delp
Language
en
File Format
application/pdf
Recommended Citation
Delp, Chad Michael, "The Syntheses and Characterizations of Samarium Arsenic Sulfide Compounds" (2002). Dissertations and Theses @ UNI. 2472.
https://scholarworks.uni.edu/etd/2472
Comments
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