The formation and structure of mechano-synthesized nanocrystalline Sr3Fe2O6.4

XRD Rietveld, Mössabuer and XPS analyses

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7 Citations (Scopus)

Abstract

The influence of ball milling and subsequent sintering of a 3:1 molar mixture of SrCO3 and α-Fe2O3 on the formation of Sr3Fe2O7-δ double perovskite is investigated with different analytical techniques. Milling the mixture for 110 h leads to the formation of SrCO3-α-Fe2O3 nanocomposites and the structural deformation of α-Fe2O3 via the incorporation of Sr2+ ions. Subsequent sintering of the pre-milled reactants' mixture has led to the partial formation of an SrFeO3 perovskite-related phase in the temperature range 400-600 °C. This was followed by the progressive development of an Sr3Fe2O7-δ phase that continued to increase with increasing sintering temperature until a single-phased nanocrystalline Sr3Fe2O7-δ phase was attained at 950 °C (12 h). This temperature is ∼350 °C lower than the temperature at which the material is prepared conventionally using the ceramic method. The evolution of different structural phases during the reaction process is discussed. Rietveld refinement of the X-ray diffraction data shows a value of 0.60 for the oxygen deficiency δ, in consistency with the Fe3+/Fe4+ ratio derived from the 57Fe Mössbauer data recorded at both 300 K and 78 K. The Mössbauer data suggests that the Sr3Fe2O6.4 nanoparticles are superparamagnetic with blocking temperatures below 78 K. The surfaces of the Sr3Fe2O6.4 nanoparticles were shown to have a complex structure and composition relative to those of their cores with traces of SrCO3, SrO and SrFeO3-δ being detected.

Original languageEnglish
Pages (from-to)142-148
Number of pages7
JournalMaterials Research Bulletin
Volume65
DOIs
Publication statusPublished - 2015

Fingerprint

X ray photoelectron spectroscopy
sintering
Sintering
Perovskite
Temperature
temperature
Nanoparticles
nanoparticles
Rietveld refinement
hypoxia
Ball milling
balls
Nanocomposites
nanocomposites
ceramics
Ions
Oxygen
X ray diffraction
Chemical analysis
diffraction

Keywords

  • Double-perovskite
  • Mechano-synthesis
  • Mössbauer spectroscopy
  • Nanostructures
  • XPS
  • XRD

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering
  • Mechanics of Materials

Cite this

@article{6f22f6b351bd40fe861783602d12c5de,
title = "The formation and structure of mechano-synthesized nanocrystalline Sr3Fe2O6.4: XRD Rietveld, M{\"o}ssabuer and XPS analyses",
abstract = "The influence of ball milling and subsequent sintering of a 3:1 molar mixture of SrCO3 and α-Fe2O3 on the formation of Sr3Fe2O7-δ double perovskite is investigated with different analytical techniques. Milling the mixture for 110 h leads to the formation of SrCO3-α-Fe2O3 nanocomposites and the structural deformation of α-Fe2O3 via the incorporation of Sr2+ ions. Subsequent sintering of the pre-milled reactants' mixture has led to the partial formation of an SrFeO3 perovskite-related phase in the temperature range 400-600 °C. This was followed by the progressive development of an Sr3Fe2O7-δ phase that continued to increase with increasing sintering temperature until a single-phased nanocrystalline Sr3Fe2O7-δ phase was attained at 950 °C (12 h). This temperature is ∼350 °C lower than the temperature at which the material is prepared conventionally using the ceramic method. The evolution of different structural phases during the reaction process is discussed. Rietveld refinement of the X-ray diffraction data shows a value of 0.60 for the oxygen deficiency δ, in consistency with the Fe3+/Fe4+ ratio derived from the 57Fe M{\"o}ssbauer data recorded at both 300 K and 78 K. The M{\"o}ssbauer data suggests that the Sr3Fe2O6.4 nanoparticles are superparamagnetic with blocking temperatures below 78 K. The surfaces of the Sr3Fe2O6.4 nanoparticles were shown to have a complex structure and composition relative to those of their cores with traces of SrCO3, SrO and SrFeO3-δ being detected.",
keywords = "Double-perovskite, Mechano-synthesis, M{\"o}ssbauer spectroscopy, Nanostructures, XPS, XRD",
author = "Al-Rawas, {A. D.} and Widatallah, {H. M.} and Al-Harthi, {S. H.} and C. Johnson and Gismelseed, {A. M.} and Elzain, {M. E.} and Yousif, {A. A.}",
year = "2015",
doi = "10.1016/j.materresbull.2015.01.026",
language = "English",
volume = "65",
pages = "142--148",
journal = "Materials Research Bulletin",
issn = "0025-5408",
publisher = "Elsevier Limited",

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TY - JOUR

T1 - The formation and structure of mechano-synthesized nanocrystalline Sr3Fe2O6.4

T2 - XRD Rietveld, Mössabuer and XPS analyses

AU - Al-Rawas, A. D.

AU - Widatallah, H. M.

AU - Al-Harthi, S. H.

AU - Johnson, C.

AU - Gismelseed, A. M.

AU - Elzain, M. E.

AU - Yousif, A. A.

PY - 2015

Y1 - 2015

N2 - The influence of ball milling and subsequent sintering of a 3:1 molar mixture of SrCO3 and α-Fe2O3 on the formation of Sr3Fe2O7-δ double perovskite is investigated with different analytical techniques. Milling the mixture for 110 h leads to the formation of SrCO3-α-Fe2O3 nanocomposites and the structural deformation of α-Fe2O3 via the incorporation of Sr2+ ions. Subsequent sintering of the pre-milled reactants' mixture has led to the partial formation of an SrFeO3 perovskite-related phase in the temperature range 400-600 °C. This was followed by the progressive development of an Sr3Fe2O7-δ phase that continued to increase with increasing sintering temperature until a single-phased nanocrystalline Sr3Fe2O7-δ phase was attained at 950 °C (12 h). This temperature is ∼350 °C lower than the temperature at which the material is prepared conventionally using the ceramic method. The evolution of different structural phases during the reaction process is discussed. Rietveld refinement of the X-ray diffraction data shows a value of 0.60 for the oxygen deficiency δ, in consistency with the Fe3+/Fe4+ ratio derived from the 57Fe Mössbauer data recorded at both 300 K and 78 K. The Mössbauer data suggests that the Sr3Fe2O6.4 nanoparticles are superparamagnetic with blocking temperatures below 78 K. The surfaces of the Sr3Fe2O6.4 nanoparticles were shown to have a complex structure and composition relative to those of their cores with traces of SrCO3, SrO and SrFeO3-δ being detected.

AB - The influence of ball milling and subsequent sintering of a 3:1 molar mixture of SrCO3 and α-Fe2O3 on the formation of Sr3Fe2O7-δ double perovskite is investigated with different analytical techniques. Milling the mixture for 110 h leads to the formation of SrCO3-α-Fe2O3 nanocomposites and the structural deformation of α-Fe2O3 via the incorporation of Sr2+ ions. Subsequent sintering of the pre-milled reactants' mixture has led to the partial formation of an SrFeO3 perovskite-related phase in the temperature range 400-600 °C. This was followed by the progressive development of an Sr3Fe2O7-δ phase that continued to increase with increasing sintering temperature until a single-phased nanocrystalline Sr3Fe2O7-δ phase was attained at 950 °C (12 h). This temperature is ∼350 °C lower than the temperature at which the material is prepared conventionally using the ceramic method. The evolution of different structural phases during the reaction process is discussed. Rietveld refinement of the X-ray diffraction data shows a value of 0.60 for the oxygen deficiency δ, in consistency with the Fe3+/Fe4+ ratio derived from the 57Fe Mössbauer data recorded at both 300 K and 78 K. The Mössbauer data suggests that the Sr3Fe2O6.4 nanoparticles are superparamagnetic with blocking temperatures below 78 K. The surfaces of the Sr3Fe2O6.4 nanoparticles were shown to have a complex structure and composition relative to those of their cores with traces of SrCO3, SrO and SrFeO3-δ being detected.

KW - Double-perovskite

KW - Mechano-synthesis

KW - Mössbauer spectroscopy

KW - Nanostructures

KW - XPS

KW - XRD

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U2 - 10.1016/j.materresbull.2015.01.026

DO - 10.1016/j.materresbull.2015.01.026

M3 - Article

VL - 65

SP - 142

EP - 148

JO - Materials Research Bulletin

JF - Materials Research Bulletin

SN - 0025-5408

ER -