Oxidation of the hexagonal Zr (Cr0.4 Fe0.6)2 Laves Phase.

P. BOZZANO; C. RAMOS; F. SAPORITI; P. VÁZQUEZ; R. VERSACI; C. SARAGOVI

JOURNAL OF NUCLEAR MATERIALS

Elsevier

Año: 2004 vol. 328 p. 225 - 231

0022-3115

The hexagonal (C14-type) Laves phase Zr(Cr0.40Fe0.60)2 when oxidized in an open furnace was studied by X-ray diffraction and M€ossbauer spectroscopy techniques. Oxidation modified part of the original Laves phase and Zr oxides, Cr oxides, á-Cr,(Fe, Cr) oxides, á-Fe and á-Fe2O3 appeared. The behaviour of these phases,particularly the Fe bearing phases,is described in detail through a two stage process (stage I from 0 to ~7 wt% O2 and stage II up to 22 wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of á-Fe upon oxidation,sustaining a model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of á-Fe upon oxidation,sustaining a model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). phases,is described in detail through a two stage process (stage I from 0 to ~7 wt% O2 and stage II up to 22 wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of á-Fe upon oxidation,sustaining a model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of á-Fe upon oxidation,sustaining a model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). Cr oxides, á-Cr,(Fe, Cr) oxides, á-Fe and á-Fe2O3 appeared. The behaviour of these phases,particularly the Fe bearing phases,is described in detail through a two stage process (stage I from 0 to ~7 wt% O2 and stage II up to 22 wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of á-Fe upon oxidation,sustaining a model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of á-Fe upon oxidation,sustaining a model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). phases,is described in detail through a two stage process (stage I from 0 to ~7 wt% O2 and stage II up to 22 wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of á-Fe upon oxidation,sustaining a model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of á-Fe upon oxidation,sustaining a model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). diffraction and M€ossbauer spectroscopy techniques. Oxidation modified part of the original Laves phase and Zr oxides, Cr oxides, á-Cr,(Fe, Cr) oxides, á-Fe and á-Fe2O3 appeared. The behaviour of these phases,particularly the Fe bearing phases,is described in detail through a two stage process (stage I from 0 to ~7 wt% O2 and stage II up to 22 wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of á-Fe upon oxidation,sustaining a model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of á-Fe upon oxidation,sustaining a model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). phases,is described in detail through a two stage process (stage I from 0 to ~7 wt% O2 and stage II up to 22 wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of á-Fe upon oxidation,sustaining a model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of á-Fe upon oxidation,sustaining a model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). model previously suggested for the oxidation of the Laves phases. This á-Fe is highly Cr-substituted. Oxidation proceeds through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). through the increasing presence of á-Fe2O3 and through the structural evolution of Zr oxides (formation of monoclinic,tetragonal and cubic ZrO2). monoclinic,tetragonal and cubic ZrO2). Cr oxides, á-Cr,(Fe, Cr) oxides, á-Fe and á-Fe2O3 appeared. The behaviour of these phases,particularly the Fe bearing phases,is described in detail through a two stage process (stage I from 0 to ~7 wt% O2 and stage II up to 22 wt% O2). A very small amount of O2 (stage I) is enough to induce the formation of