Microscale preparation and characterization of selected lanthanide and actinide phosphates

Author

Stephanie Ann Morris

Date of Award

12-1981

Degree Type

Thesis

Degree Name

Master of Science

Major

Chemistry

Major Professor

Joseph R. Peterson

Committee Members

Paul G. Huray, G. Davis O'Kelley

Abstract

Selected lanthanide and actinide phosphates were prepared on the microscale from reaction of a lead pyrophosphate (Pb₂P₂O₇) flux medium or boron phosphate (BPO₄) reagent with corresponding lanthanide and actinide oxides. Characterization of these phosphates involved X-ray diffraction and both absorption and laser Raman spectrophotometric analyses. When heated in the Pb₂P₂O₇ flux, cerium dioxide (Ce0₂) was not reduced to form the corresponding orthophosphate, CePO₄. Higher oxides of praseodymium and terbium were reduced to the orthophosphate, however. Correlation of these experimental results with published reduction potentials of the M(IV)/M(III) couples of the lanthanides and actinides allowed a prediction to be made: only americium of the actinides uranium, neptunium, plutonium, and americium would form the orthophosphate by reaction of the corresponding actinide dioxide with Pb₂P₂O₇). The prediction was confirmed experimentally and the other actinide products were tentatively identified as actinide(IV) pyrophosphates, e.g., UP₂O₇. The significance of these results lies in the ultimate goal of this area of research: to prepare transamericium orthophosphates, especially EsPO₄, for characterization and for determination of the chemical and physical consequences of their radioactive decay.

Recommended Citation

Morris, Stephanie Ann, "Microscale preparation and characterization of selected lanthanide and actinide phosphates. " Master's Thesis, University of Tennessee, 1981.
https://trace.tennessee.edu/utk_gradthes/15258