Influence of annealing treatment on magnetic properties of Fe2O3/SiO2 and formation of ε-Fe2O3 phase

Abstract Magnetic properties of Fe 2 O 3 /SiO 2 samples were studied after being produced by sol-gel synthesis and formation of e-Fe 2 O 3 polymorph. Samples were thermally treated, using different annealing temperatures and annealing times. The size and morphological characteristics of the iron oxide nanoparticles were examined using a TEM microscope. We used the “ellipticity of shapes”, which is a measure of how much the shape of a nanoparticle differs from a perfect ellipse, in order to quantitatively describe morphological properties of nanoparticles. Coercivity measurements were used to identify and monitor the formation of the epsilon-iron oxide phase during the thermal treatments (annealing). Coercivity values were in the range from 1.2 to 15.4 kOe, which is in accordance with previous experience regarding the existence of e-Fe 2 O 3 . We have determined the optimal formation conditions for the e-Fe 2 O 3 polymorph (t=1050 °C for 7 h, H C =15.4 kOe), as well as the narrow temperature interval (1050–1060 °C) in which the polymorph abruptly vanished (H C =2300 Oe), on the basis of results of the magnetic properties. The threshold temperature for the e-Fe 2 O 3 phase transformation was measured as 1060 °C. We found that different annealing temperatures and annealing times significantly affected magnetic properties of the examined samples.

[1]  B. Pacewska,et al.  Thermal transformations of aluminium nitrate hydrate , 2002 .

[2]  M. Klementová,et al.  The magnetic transition in ε-Fe2O3 nanoparticles: Magnetic properties and hyperfine interactions from Mössbauer spectroscopy , 2015 .

[3]  Libor Machala,et al.  Polymorphous Transformations of Nanometric Iron(III) Oxide: A Review , 2011 .

[4]  M. Bououdina,et al.  One-Pot Low Temperature Synthesis and Characterization Studies of Nanocrystalline α-Fe2O3 Based Dye Sensitized Solar Cells. , 2015, Journal of nanoscience and nanotechnology.

[5]  G. Hadjipanayis.  Magnetic Hysteresis in Novel Magnetic Materials , 1997 .

[6]  R. Perzynski,et al.  "Nanocasting": using SBA-15 silicas as hard templates to obtain ultrasmall monodispersed gamma-Fe2O3 nanoparticles. , 2006, The journal of physical chemistry. B.

[7]  A. Manikandan,et al.  Comparative Studies of Microwave- and Sol-Gel-Assisted Combustion Methods of Fe3O4 Nanostructures: Structural, Morphological, Optical, Magnetic, and Catalytic Properties , 2015 .

[8]  M. Sierka,et al.  Structure evolution of nanoparticulate Fe2O3. , 2015, Nanoscale.

[9]  D. Niznansky,et al.  Thermal stability of nanocrystalline ε-Fe2O3 , 2014, Journal of Thermal Analysis and Calorimetry.

[10]  A. Sivkov,et al.  Plasma dynamic synthesis and obtaining ultrafine powders of iron oxides with high content of ε-Fe 2 O 3 , 2016 .

[11]  Stuart A. Wolf,et al.  Spintronics - A retrospective and perspective , 2006, IBM J. Res. Dev..

[12]  A. Manikandan,et al.  Room Temperature Ferromagnetism of Magnetically Recyclable Photocatalyst of Cu1−xMnxFe2O4-TiO2 (0.0 ≤ x ≤ 0.5) Nanocomposites , 2015 .

[13]  Lide Zhang,et al.  The thermal stability of nanocrystalline maghemite , 1998 .

[14]  K. Hashimoto,et al.  Giant Coercive Field of Nanometer‐ Sized Iron Oxide , 2004 .

[15]  Paul E. Sheehan,et al.  Design and Performance of GMR Sensors for the Detection of Magnetic Microbeads in Biosensors , 2003 .

[16]  J. Dormann,et al.  Magnetic Properties of Fe2O3 Particles Prepared by Sol-Gel Method , 1998 .

[17]  A. Manikandan,et al.  Magneto-Optical and Photocatalytic Properties of Magnetically Recyclable MnxZn1−xS(x = 0.0, 0.3, and 0.5) Nanocatalysts , 2015 .

[18]  C. Gan,et al.  Ultrathin β-FeOOH and ɛ-Fe2O3 nanowires , 2014 .

[19]  K. Yano,et al.  Novel synthesis of highly monodispersed γ-Fe2O3/SiO2 and ε-Fe2O3/SiO2 nanocomposite spheres , 2006 .

[20]  A. Manikandan,et al.  A Novel Synthesis, Structural, Morphological, and Opto-magnetic Characterizations of Magnetically Separable Spinel CoxMn1−xFe2O4 (0 ≤ x ≤ 1) Nano-catalysts , 2014 .

[21]  S. Nayar,et al.  Multi-functional biomimetic graphene induced transformation of Fe3O4 to ε-Fe2O3 at room temperature , 2015 .

[22]  G. A. Bukhtiyarova,et al.  Facile synthesis of nanosized ε-Fe2O3 particles on the silica support , 2011 .

[23]  Ch. Simon,et al.  Magnetoelectric coupling in ε-Fe2O3 nanoparticles , 2006 .

[24]  K. Hashimoto,et al.  First observation of phase transformation of all four Fe(2)O(3) phases (gamma --> epsilon --> beta --> alpha-phase). , 2009, Journal of the American Chemical Society.

[25]  J. Vijaya,et al.  Structural, optical and magnetic properties of porous alpha-Fe2O3 nanostructures prepared by rapid combustion method. , 2013, Journal of nanoscience and nanotechnology.

[26]  Multiferroic Iron Oxide Thin Films at Room Temperature , 2014, Advanced materials.

[27]  S. Vilminot,et al.  Formation of Nanoparticles of ε-Fe2O3 from Yttrium Iron Garnet in a Silica Matrix: An Unusually Hard Magnet with a Morin-Like Transition below 150 K , 2005 .

[28]  A. Teja,et al.  Synthesis, properties, and applications of magnetic iron oxide nanoparticles , 2009 .

[29]  K. Barick,et al.  Structural and magnetic properties of γ- and ε-Fe2O3 nanoparticles dispersed in silica matrix , 2010 .

[30]  G. A. Bukhtiyarova,et al.  Formation conditions of a magnetically ordered phase ɛ-Fe2O3. A FMR in situ study , 2013, Journal of Structural Chemistry.

[31]  G. A. Bukhtiyarova,et al.  Surface effects and magnetic ordering in few-nanometer-sized ε-Fe2O3 particles , 2013 .

[32]  S. Vilminot,et al.  A temperature and magnetic field dependence Mössbauer study of ɛ-Fe2O3 , 2006 .

[33]  K. Hashimoto,et al.  Reorientation phenomenon in a magnetic phase of ε-Fe2O3 nanocrystal , 2005 .

[34]  V. Murthy,et al.  Ferrite Materials: Science and Technology , 1991 .

[35]  A. Manikandan,et al.  A Novel Synthesis of Zn2+-Doped CoFe2O4 Spinel Nanoparticles: Structural, Morphological, Opto-magnetic and Catalytic Properties , 2015 .

[36]  A. Manikandan,et al.  One-Pot Flash Combustion Synthesis, Structural, Morphological and Opto-Magnetic Properties of Spinel MnxCo1−xAl2O4 (x = 0, 0.3, and 0.5) Nanocatalysts , 2015 .

[37]  S. Jaganathan,et al.  Enhanced Catalytic Activity and Magnetic Properties of Spinel MnxZn1−xFe2O4 (0.0 ≤ x ≤ 1.0) Nano-Photocatalysts by Microwave Irradiation Route , 2016 .

[38]  R. Zbořil,et al.  Thermally Induced Solid-State Syntheses of γ-Fe2O3 Nanoparticles and Their Transformation to α-Fe2O3 via ε-Fe2O3 , 2002 .

[39]  D. Peeters,et al.  Surface Decoration of ϵ‐Fe2O3 Nanorods by CuO Via a Two‐Step CVD/Sputtering Approach** , 2014 .

[40]  G. Carraro,et al.  Determination of thermooptical and transport parameters of e iron(III) oxide-based nanocomposites by beam deflection spectroscopy , 2015 .

[41]  A. Manikandan,et al.  Mn2+ Doped NiS (MnxNi1−xS: x = 0.0, 0.3 and 0.5) Nanocrystals: Structural, Morphological, Opto-magnetic and Photocatalytic Properties , 2015, Journal of Inorganic and Organometallic Polymers and Materials.

[42]  A. A. Krasikov,et al.  Dynamic magnetization of e-Fe2O3 in pulse field: Evidence of surface effect , 2015 .

[43]  D. Peeters,et al.  Solar H2generation via ethanol photoreforming on ε-Fe2O3nanorod arrays activated by Ag and Au nanoparticles , 2014 .

[44]  M. Durka,et al.  A Novel One-Pot Combustion Synthesis and Opto-magnetic Properties of Magnetically Separable Spinel MnxMg1−xFe2O4(0.0 ≤ x ≤ 0.5) Nanophotocatalysts , 2015 .

[45]  J. Vijaya,et al.  Microwave combustion synthesis, structural, optical and magnetic properties of Zn1−xSrxFe2O4 nanoparticles , 2013 .

[46]  K. Hashimoto,et al.  Large coercive field in magnetic-field oriented ε-Fe2O3 nanorods , 2008 .

[47]  S. Jaganathan,et al.  Spinel NixZn1-xFe2O4 (0.0 ≤ x ≤ 1.0) nano-photocatalysts: Synthesis, characterization and photocatalytic degradation of methylene blue dye , 2016 .

[48]  Zhong Lin Wang,et al.  PLD-assisted VLS growth of aligned ferrite nanorods, nanowires, and nanobelts-synthesis, and properties. , 2006, The journal of physical chemistry. B.

[49]  D. Shah,et al.  Synthesis of high-coercivity cobalt ferrite particles using water-in-oil microemulsions , 1996 .

[50]  J. Coey,et al.  Magnetic and thermal properties of ϵ-Fe2O3 , 1973 .

[51]  G. A. Bukhtiyarova,et al.  Size effects in the magnetic properties of ε-Fe2O3 nanoparticles , 2015 .

[52]  J. López-Sánchez,et al.  Sol–Gel Synthesis and Micro-Raman Characterization of ε-Fe2O3 Micro- and Nanoparticles , 2016 .

[53]  S. Ramakrishna,et al.  A simple aloe vera plant-extracted microwave and conventional combustion synthesis: Morphological, optical, magnetic and catalytic properties of CoFe2O4 nanostructures , 2014 .

[54]  J. Tuček,et al.  ε-Fe2O3: An Advanced Nanomaterial Exhibiting Giant Coercive Field, Millimeter-Wave Ferromagnetic Resonance, and Magnetoelectric Coupling , 2010 .

[55]  J. Vijaya,et al.  Synthesis, optical and magnetic properties of pure and Co-doped ZnFe2O4 nanoparticles by microwave combustion method , 2014 .

[56]  D. Schmeißer,et al.  Spin state and satellite structures of ε-Fe2O3 as determined by resonant photoelectron spectroscopy , 2015 .

[57]  O. Koplak,et al.  Epsilon-phase iron(III) oxide nanowires for a magnetic-resonance spin-current source , 2015, Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques.

[58]  U. Schwertmann,et al.  The Iron Oxides: Structure, Properties, Reactions, Occurrences and Uses , 2003 .

[59]  N. Pizúrová,et al.  ε-Fe2O3 nanoparticles synthesized in atmospheric-pressure microwave torch , 2014 .

[60]  J. Vijaya,et al.  Structural, optical and magnetic properties of Fe3O4 nanoparticles prepared by a facile microwave combustion method , 2014 .

[61]  K. Hashimoto,et al.  The addition effects of alkaline earth ions in the chemical synthesis of ε-Fe2O3 nanocrystals that exhibit a huge coercive field , 2005 .

[62]  M. Nakajima,et al.  High-frequency millimeter wave absorption of indium-substituted ε-Fe2O3 spherical nanoparticles (invited) , 2014 .

[63]  A. Roig,et al.  Nonzero orbital moment in high coercivity γ-Fe 2 O 3 and low-temperature collapse of the magnetocrystalline anisotropy , 2009 .

[64]  S. Gyergyek,et al.  Quantifying shapes of nanoparticles using modified circularity and ellipticity measures , 2016 .

[65]  W. Kean,et al.  Botanical iron minerals correlation between nanocrystal structure and modes of biological self-assembly , 2001 .

[66]  J. Vijaya,et al.  Optical and magnetic properties of Mg-doped ZnFe2O4 nanoparticles prepared by rapid microwave combustion method , 2013 .

[67]  A. Manikandan,et al.  Hibiscus rosa-sinensis Leaf Extracted Green Methods, Magneto-Optical and Catalytic Properties of Spinel CuFe2O4 Nano- and Microstructures , 2015, Journal of Inorganic and Organometallic Polymers and Materials.

[68]  D. Peeters,et al.  Au/ε-Fe2O3 Nanocomposites as Selective NO2 Gas Sensors , 2014 .

[69]  A. Manikandan,et al.  Fundamental study of LaMgxCr1−xO3−δ perovskites nano-photocatalysts: Sol-gel synthesis, characterization and humidity sensing , 2016, Korean Journal of Chemical Engineering.

[70]  Kenta Imoto,et al.  Nanometer-size hard magnetic ferrite exhibiting high optical-transparency and nonlinear optical-magnetoelectric effect , 2015, Scientific Reports.

[71]  K. Hashimoto,et al.  Synthesis, Crystal Structure, and Magnetic Properties of ϵ‐InxFe2–xO3 Nanorod‐Shaped Magnets , 2007 .

[72]  H. Yashiro,et al.  Preparation of the Nanowire Form of ε-Fe2O3 Single Crystal and a Study of the Formation Process , 2008 .

[73]  A. Manikandan,et al.  Role of Mn2+ Doping on Structural, Morphological, and Opto-Magnetic Properties of Spinel MnxCo1−xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) Nanocatalysts , 2015 .

[74]  M. Remškar,et al.  Formation of ε-Fe2O3 phase by the heat treatment of α-Fe2O3/SiO2 nanocomposite , 2008 .

[75]  A. Roig,et al.  Optimized Synthesis of the Elusive ε-Fe2O3 Phase via Sol−Gel Chemistry , 2004 .

[76]  A. Manikandan,et al.  Electromagnetic Properties and Humidity-Sensing Studies of Magnetically Recoverable LaMgxFe1−xO3−δ Perovskites Nano-photocatalysts by Sol-Gel Route , 2016 .

[77]  R. Schrader,et al.  Untersuchungen über γ‐Eisen(III)‐oxid , 1963 .

[78]  E. Tronc,et al.  Structural and Magnetic Characterization ofε-Fe2O3 , 1998 .

[79]  S. Pennycook,et al.  Epitaxial stabilization of ε-Fe2O3 (00l) thin films on SrTiO3 (111) , 2010 .