Students: Markus Vasquez (Oklahoma State U.) and Lucas Wilson (Wisconsin-Stevens Point)

Mentor: John Farley

A Study of Spinels, NiFe_xCr_(2-x)O₄, by Laser Micro-Raman Spectroscopy

It has been proposed to transmute radioactive waste by neutron bombardment. Whether or not transmutation is practical is crucially dependent on materials questions. Liquid metals such as lead-bismuth eutectic corrodes steel. Our research group has been examining the fundamentals of the corrosion process. Spinels are oxides of two metals with the formula AB₂O_4. Spinels are believed to be produced in the corrosion of steel by liquid metal. Our goal is to identify the chemical products of corrosion in order to understand the corrosion process. Standard samples of iron nickel chromium spinels with known composition have been synthesized. The samples have been examined by Laser Micro-Raman spectroscopy, which identifies the chemical species by measuring the characteristic vibrational modes. A total of 22 samples of spinels, with formula NiFe_xCr_(2-x)O_4, were produced, and over 50 spectra acquired. Changes in the Raman spectra with composition were clearly evident. Several samples were examined using x-ray diffraction, yielding a pattern consistent with the spinel structure