Thermal Reactions of the Mixed-Valence Iron Fluorides, Fe2F5.nH2O.

Abstract

The thermal reactions of Fe2F5.7H2O and Fe2F5.2H2O have been studied using a combination of thermogravimetric, differential thermogravimetric, and differential thermal analysis and by differential scanning calorimetry. The initial dehydration of Fe2F5.7H2O near 100 C is shown to be a complex process which leads to a fluoride-deficient phase of nominal composition Fe2F5.2H2O. Further heating leads to a product at the hemihydrate level. Isothermal dehydrations lead to the previously reported phases A and B, but the formation of these materials is accompanied by both oxidation and fluoride loss. Vacuum dehydration of F2eF5.7H2O leads to a fully mixed-valence monohydrate phase, A', which was previously prepared by dehydration in an HF atmosphere. Dehydration of the authentic, crystalline, Fe2F5.2H2O is seen to be distinguishable from the second stage dehydration of Fe2F5.7H2O. Both the thermogravimetric analyses and the kinetic parameters extracted from the several thermal techniques demonstrate that these two forms of 'Fe2F5.2H2O' differ significantly in their thermal reactions. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Apr 07, 1978
Accession Number
ADA052673

Entities

People

  • David B. Brown
  • Erick G. Walton
  • Joseph A. Dilts

Organizations

  • University of Vermont

Tags

Communities of Interest

  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Body Weight
  • Chemical Analysis
  • Chemistry
  • Differential Thermal Analysis
  • Diffraction
  • Energy
  • Equations
  • Heat Of Activation
  • Low Temperature
  • Materials
  • Measurement
  • Military Research
  • North Carolina
  • Physical Properties
  • Reaction Orders
  • Thermal Analysis
  • X Rays

Fields of Study

  • Materials science

Readers

  • Combustion science or combustion engineering.
  • Materials Science and Engineering.
  • Organic Chemistry