Exploring structural and magnetic properties of nanocrystalline iron oxide synthesized by autocombustion method

被引：17

作者：

Rajpure, K. Y. ^{[1
]}

机构：

[1] Shivaji Univ, Dept Phys, Electrochem Mat Lab, Kolhapur 416004, Maharashtra, India

来源：

SUPERLATTICES AND MICROSTRUCTURES | 2015年 / 77卷

关键词：

Hematite; Maghemite; Rietveld refinement; X-ray photoelectron spectroscopy; Mossbauer spectroscopy; COMBUSTION SYNTHESIS; ALPHA-FE2O3; NANOSTRUCTURES; THERMAL-DECOMPOSITION; XPS SPECTRA; NANOPARTICLES; REFINEMENT; SUBSTITUTION; PARTICLES; MECHANISM; GROWTH;

D O I：

10.1016/j.spmi.2014.11.012

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

The nanocrystalline Fe2O3 is synthesized by solution autocombustion method using glycine as a fuel. The Rietveld refinement results confirm that the as prepared powder is a mixture of Hematite (alpha-Fe2O3, 80.50 wt%) and Maghemite (gamma-Fe2O3, 19.50 wt%) phases and annealed (1000 degrees C for 5 h) powder is a single hematite phase of Fe2O3. The A(1g) symmetry bands are observed at 227 and 502 cm(-1) and E-g symmetry bands are observed at 293, 411, and 611 cm(-1) in hematite phase of Fe2O3. Chemical composition and valence state of the samples was confirmed using XPS studies. It is found that samples are sub-stoichiometric and broadening in the Fe 2p doublet is due to the multiplet splitting effects evidencing unpaired valence electrons. Fe-57 Mossbauer spectroscopy analysis was used to further characterize the samples and confirm stoichiometry. Both the samples exhibit magnetically hyperfine split spectra with some special features. The annealed sample indicates the presence of only tetrahedral and octahedral site cations in hematite. The magnetic properties of the samples were studied by using M-H hysteresis curves. The saturation magnetizations of as prepared and annealed samples are 55.22 and 6.36 emu/g, respectively. Annealed sample exhibited larger value of coercivity (1065.6 Oe) and squareness (0.50) compared to the as prepared one (229.25 Oe, 0.28 respectively). (C) 2014 Elsevier Ltd. All rights reserved.

引用

页码：181 / 195

页数：15

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