6533b863fe1ef96bd12c7901

RESEARCH PRODUCT

A Raman spectroscopy study of the oxidation processes in synthetic chromite FeCr2O4

Valter SergoFrancesco PrincivalleVanni LughiAlois BonifacioFilippo ParisiFilippo ParisiDavide LenazDavide Lenaz

subject

Materials scienceRaman mappingAnnealing (metallurgy)Scanning electron microscopeSpinelHematite02 engineering and technologyRaman mapping01 natural sciencesMagnetitechemistry.chemical_compoundsymbols.namesake0103 physical sciencesOxidationMaterials ChemistryMagnetite010302 applied physicsProcess Chemistry and TechnologyChromiteHematite021001 nanoscience & nanotechnologySpinel; Chromite; Magnetite; Hematite; Oxidation; Raman mappingSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialschemistryChemical engineeringvisual_artCeramics and Compositessymbolsvisual_art.visual_art_mediumChromiteOxidation process0210 nano-technologyRaman spectroscopy

description

Abstract A crystal of synthetic chromite FeCr2O4 has been annealed in air at 700 °C for 50 days at room pressure in order to study physical-chemical changes. After the annealing treatment, Scanning Electron Microscopy (SEM) images of the polished surface of the sample showed areas of different composition. Detailed Raman mapping revealed that the annealed chromite undergoes an oxidation process, proceeding inwards from the outer surface and leading to the transformation of chromite to magnetite, and ultimately to hematite. The oxidation process also leads to the formation of trellis-like lines, arguably via stress-related mechanisms associated with the phase transformation and consequent volume changes. The present study confirms the possibility of non-stoichiometry or structural defects causing slight structural asymmetries and the formation of new modes, resulting in a valuable support in characterizing both natural and artificial material. The potential of Raman spectroscopy in the identification and spatial resolution of mineralogical phases, is also highlighted.

yearjournalcountryeditionlanguage
2020-12-01
10.1016/j.ceramint.2020.07.059http://hdl.handle.net/11368/2970197