Sol-gel preparation of transition metal, lanthanide, and actinide silicate glasses
Binary transition metal (Cr(III), (VI), Mn(II),(III) and Ni(II)), lanthanide (Pr(III), Tb(III), Dy(III) and Er(III)) and actinide (U(VI) and Th(IV)) silicated glasses have been obtained by sol-gel methods starting with various metal sources and TEOS (tetraethoxysilane). Metal carbonates were used for the transition metal and lanthanide silicate glasses, and metal oxide or hydroxide was used for the actinide silicate glasses. Expressed in the form xM{sub a}O{sub b}{center dot} (1 {minus}x)SiO{sub 2}, the glasses have compositions in the range x = 0.0012-0.0562 (Cr, Mn and Ni), x = 0.009-0.052 (Pr, Tb, Dy and Er) and x = 0.0017-0.0468 (U and Th) or up to about 23 weight percent rare earth oxide as determined by electron microprobe. The glasses were produced by densification at temperature of 600-800{degree}C. Partial crystallization of uranium silicate occurs on heating at 700{degree}C or above. The oxidative stabilities of lanthanide and actinide ions were high enough for them to withstand the drying and densifying stages of the gel to glass transformation without change in oxidation state, but the transition metal ions presented a more complicated situation, because of their accessible oxidation states, coordination numbers and geometries. The infrared and near infrared spectra were obtained to probe the OH content and the network formation. The ultraviolet - visible - near infrared spectra of gels and glasses were used to probe the oxidation states and coordination of the metal ion, and were interpreted in terms on ligand field theory. The magnetic susceptibilities supported the results of the absorption spectral studies. All glasses were amorphous by both x-ray diffraction and electron microprobe measurement, and free of chlorine to within the limit of the microprobe sensitivity.
- Research Organization:
- Brown Univ., Providence, RI (United States)
- OSTI ID:
- 7039542
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
METALLIC GLASSES
CHEMICAL PREPARATION
SILICATES
ABSORPTION SPECTROSCOPY
ACTINIDES
CHARGE STATE
CHROMIUM OXIDES
DYSPROSIUM OXIDES
ELECTRON MICROPROBE ANALYSIS
ERBIUM OXIDES
EXPERIMENTAL DATA
LIGANDS
MAGNETIC SUSCEPTIBILITY
MANGANESE OXIDES
MICROANALYSIS
NEAR INFRARED RADIATION
NICKEL OXIDES
PRASEODYMIUM OXIDES
QUANTITY RATIO
RARE EARTHS
SOL-GEL PROCESS
TERBIUM OXIDES
THORIUM OXIDES
TRANSITION ELEMENTS
ULTRAVIOLET RADIATION
URANIUM OXIDES
VISIBLE RADIATION
X-RAY DIFFRACTION
ACTINIDE COMPOUNDS
CHALCOGENIDES
CHEMICAL ANALYSIS
CHROMIUM COMPOUNDS
COHERENT SCATTERING
DATA
DIFFRACTION
DYSPROSIUM COMPOUNDS
ELECTROMAGNETIC RADIATION
ELEMENTS
ERBIUM COMPOUNDS
INFORMATION
INFRARED RADIATION
MAGNETIC PROPERTIES
MANGANESE COMPOUNDS
METALS
NICKEL COMPOUNDS
NONDESTRUCTIVE ANALYSIS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PRASEODYMIUM COMPOUNDS
RADIATIONS
RARE EARTH COMPOUNDS
SCATTERING
SILICON COMPOUNDS
SPECTROSCOPY
SYNTHESIS
TERBIUM COMPOUNDS
THORIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
URANIUM COMPOUNDS
360601* - Other Materials- Preparation & Manufacture
360602 - Other Materials- Structure & Phase Studies
360606 - Other Materials- Physical Properties- (1992-)
400702 - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials
400102 - Chemical & Spectral Procedures