Mossbauer spectroscopy in the equiatomic ternary systems UFeGa and UFeAl

Includes bibliographical references.Includes illustrations.Mossbauer measurements hare been made at Fe⁵⁷ nuclei in the equlatomic systems UFeGa said UFeAl. These ternary systems are from a recently discovered family with Pe₂P-type structure containing a rare earth or actinide component. The stability of the compound has been attributed to both size factors and electron concentration e/a and, Indeed, these factors are Identical In the two compounds. The U atoms occur In the A layer, Al or Ga in B, and Fe In both. Iron substitutes for phosphorus In the prototype structure and goes into two nonequivalent sites of low symmetry. The quadrupole splitting and Isomer shift have been measured as a function of temperature. It Is found that contrary to expectation that the electronic state of the iron near neighbor of U is considerably different between compounds. A suggested explanation is given on the basis of the actinide electronic configuration.M.S. (Master of Science