research presentation gerardo ramos otero jun2014
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Research Presentation Gerardo Ramos Otero Jun2014TRANSCRIPT
Solid-state synthesis and characterization of low-melting
mixed-metal oxides
GERARDO P. RAMOS OTERO
PRINCIPAL INVESTIGATOR: DR. L. KOSCIELSKI
University of Puerto Rico at Cayey
Outline
Solid-state Chemistry Background
Solid-state Synthesis Methodology
Future Work Acknowledgements
Solid-state Chemistry Background
Solid-state Chemistry
Solid-state Synthesis High Temperature
Starting Materials (powders, granules, crystals)
Process
Bond Disruption (high temperatures)
Rearrangement
Reformation (cooling)
Solid-state Chemistry Background
Low melting mixed metal oxides Ternary Compounds
MxM’yOz
Oxides At least one oxygen atom and one other
element in its chemical formula Oxygen in the oxidation state of −2 Electrical conductivity and optical
transparency
Solid-state Chemistry Background
Low Melting Metals
Solid-state Synthesis Methodology
Synthesis Vessel Preparation
Silica Tubes
Loading of Reagents Silica Tubes
Atmosphere
Glove-box
Heating of Reactions Computer-controlled furnace
Heating Step
Plateau Step
Slow-cooling Step
Trial and Error Approach
Solid-state Synthesis Methodology
Structural Determination
X-ray Spectroscopy
Powders and Crystals
Elemental Composition
Stoichiometry
Product
Powder
Powder X-ray diffraction
Novel Compound
Reload into silica tubes with
crystallizing agent
Crystal
Single-crystal X-ray diffraction
Previously Synthesized
Crystal
Single-crystal X-ray diffraction
Solid-state Synthesis Methodology
Physical Properties Determination Depends on the compound
Resistivity
Magnetic Properties
Thermopower
Ternary low-melting mixed-metal oxides already created
Loaded Reactions Groups 14/14
Loaded Reactions Groups 14/15
Synthesize new ternary compounds that contain two metals and an oxygen atom using previous synthesis methodology.
2In2O3 + 3SnO2 In4Sn3O12 (Already
synthesized)
2Ga2O3 + 3GeO2 Ga4Ge3O12
Characterize these compounds structurally via powder and single-crystal X-ray diffraction methods.
Determine selected physical properties such as magnetic susceptibilities, conductivity, resistivity, and thermopower.
Future Work
1,400 oC, 10h
1,400 oC, 10h
Future Work
Synthesis Methodology: 1. M + M’2O3 at 226.85oC for 10d
2. M2O3 + M’O2 at 1000oC for 2-3h
Future Work
Method 1
Future Work
Method 2
Acknowledgments
University of Puerto Rico at Cayey
RISE Program (Research Initiative for Scientific Enhancement)
BRIC
III (Instituto de Investigaciones Interdisciplinarias)
Dr. L. Koscielski
Solid-state synthesis and characterization of low-melting
mixed-metal oxides
GERARDO P. RAMOS OTERO
PRINCIPAL INVESTIGATOR: DR. L. KOSCIELSKI
University of Puerto Rico at Cayey
Conductivity and Resistivity
X-ray Spectroscopy