Fe-doped Samples Research Articles

Structural and magnetic properties of Fe-doped SnS2 nanopowders synthesized by solid-state reaction method

A facile solid-state reaction method has been employed to synthesize pure and Fe-doped SnS2 nanopowders. The as-synthesized samples show the nanosheet morphology and polycrystalline nature, as characterized by TEM. The existence of Fe in the doped samples has been corroborated by XPS and EDS. The measurement results show that the Fe-doped SnS2 samples present weak ferromagnetic orderings in addition to enhanced paramagnetic orderings. It is deduced that the joint effect of the intralayered and interlayered Fe atoms leads to the changes in the magnetic properties. Furthermore, the enhanced magnetic properties will make Fe-doped SnS2 promising for spintronic devices application.

Iridium-related complexes in Czochralski-grown β-Ga2O3

Gallium oxide is a promising semiconductor for its potential as a material in the field of power electronics. The effects of iridium impurities on undoped, Mg-doped, and Ca-doped gallium oxides were investigated with IR spectroscopy. In undoped and Ca-doped β-Ga2O3, IR peaks at 3313, 3450, and 3500 cm−1 are tentatively assigned to O–H bond-stretching modes of IrH complexes. Mg-, Ca-, and Fe-doped samples show an Ir4+ electronic transition feature at 5148 cm−1. By measuring the strength of this feature vs photoexcitation, the Ir3+/4+ donor level was determined to lie 2.2–2.3 eV below the conduction band minimum. Ga2O3:Mg also has a range of sidebands between 5100 and 5200 cm−1, attributed to IrMg pairs. Polarized IR measurements show that the 5248 cm−1 peak is anisotropic, weakest for light polarized along the c axis, consistent with Lenyk et al. [J. Appl. Phys. 125, 045703 (2019)].

CO2 methanation on transition-metal-promoted Ni-Al catalysts: Sulfur poisoning and the role of CO2 adsorption capacity for catalyst activity

Co-precipitated and promoted Ni-Al catalysts, specifically Mn- and Fe-doped systems, rank among the most active and thermostable catalysts for the CO2 methanation reaction. However, little is known about the resistance of those catalysts against sulfur poisoning and the exact reasons for activity enhancement. In order to resolve these questions, a co- precipitated Ni-Al benchmark catalyst with a Ni loading of 41 wt% was promoted by up to 5 wt% of Mn, Fe, Co, Cu and Zn. CO2 methanation activity and stability against sulfur poisoning was evaluated by in situ poisoning with 5 ppm of H2S and ex situ poisoning with liquid (NH4)2S. Characterization results obtained from XRD, TPR, N2 physisorption, H2 and CO2 chemisorption contributed to derive structure- activity relationships. All promoted samples show a superior resistance versus H2S poisoning, which is correlated to H2S adsorption on promoter phases, protecting active Ni sites. Based on the adsorption properties of spent in situ poisoned samples, the individual CO2 uptake of the Ni0 and the promoter phase were identified and correlated to CO2 methanation activities of ex situ poisoned samples. Enhanced activities of Mn- and Fe-doped samples are ascribed to CO2 adsorption on promoter phases and subsequent conversion to CH4. In contrast, CO2 adsorbed on Cu is converted to CO, causing severe catalyst deactivation. Regarding activity, Co and Zn have insignificant impact. Apparent activation energies of all samples are similar and in the range of 81–92 kJ/mol. Sulfur poisoning and promoter-induced activity changes are therefore ascribed to structural rather than electronic effects for the investigated promoter loadings.

Incompatible magnetic and dielectric properties of BiCu3-xMnxTi4-yMyO12 (x = 0 & 0.5; y = 1 & 1.5 and M = Fe & Mn)

Here we report ambient pressure synthesis, magnetic and dielectric properties of BiCu3Ti3(Fe/Mn)O12 and BiCu2.5Mn0.5Ti2.5Fe1.5O12. Both the samples are crystallized in a cubic Im-3 space group. The antiferromagnetic ground state of A-site copper in Bi2/3Cu3Ti4O12 is differently affected by substitution of nonmagnetic Ti4+ by magnetic Fe and Mn ions in B-site. In contrast to the Mn substitution, the antiferromagnetic ordering of A-site Cu is robust towards Fe substitution. The substitution of iron for Ti4+ initially weakens the antiferromagnetic structure of A-site Cu and eventually it results in the crossover from antiferromagnetic to ferrimagnetic state, whereas the Mn substitution quickly turns antiferromagnetic to ferrimagnetic state. For x > 1.0 Fe-doped sample and low Mn-doped samples exhibit phase separation where the ferromagnetic like phase coexists with antiferromagnetic phase. The glassy magnetic state is realized for x = 1.0 Fe doped sample. The magnetic ground state strongly influences the dielectric behavior of the samples. Near room temperature the dielectric constant value is ~2000 for BiCu3Ti3FeO12, whereas for BiCu2.5Mn0.5Ti2.5Fe1.5O12 the value is much lower (<600) with higher dielectric loss. The leaky nature in magnetically phase separated BiCu2.5Mn0.5Ti2.5Fe1.5O12 can be ascribed to the opening of conducting ferrimagnetic channels. The present investigation revealed that in quadruple perovskite the magnetic and dielectric properties are incompatible where improvement of magnetic response eventually suppresses the dielectric behavior.

Enhanced photocatalytic Activity of Ferromagnetic Fe-doped NiO nanoparticles

The Ni1-xFexO (x = 0.00, 0.02, 0.04, 0.06 and 0.08) nanoparticles (NPs) has been synthesized via composite hydroxide mediated (CHM) synthesis approach. The single phase formation of NiO NPs was achieved without any impurity phase confirmed by XRD and average crystallite size showed minor decreasing trend with increasing Fe doping concentration. FTIR spectra showed dip in 417-432 cm−1 range which confirmed the existence of Ni-O bonding. In Raman spectra, the weak two-magnon (2 M) band at 1472 cm−1 in pure NiO NPs indicate suppressed antiferromagnetism (AFM) due to smaller average crystallite size and superparamagnetic contribution from the uncompensated surface/core spins. The absence of 2 M band in Fe doped samples is due to onset of ferromagnetism in these NPs. The M-H loops showed the room temperature ferromagnetism in Fe doped samples due to double exchange interaction of mixed valance states of Fe. The energy band gap showed minor increasing trend with increasing Fe doping concentration and is mainly attributed to Moss-Burstein effect. The photocatalytic activity showed an increasing trend with increasing Fe doping due to generation oxygen vacancies which served as energy traps and restricted the electron-hole recombination. Therefore, the bifunctional ferromagnetic Fe doped NiO NPs are more favourable for photocatalysis along with their ability of collection for re-use in the degradation process.

Fe-doped ZnO nanoparticles as novel photonic and multiferroic semiconductor

Fe-doped ZnO nanoparticles were synthesized through the chemical method of sol-gel technique. XRD and its Rietveld refinement, high resolution TEM, Electron Diffraction Spectroscopy (EDS) and FTIR spectroscopy have been carried out to obtain the crystal structure, crystal growth direction, surface morphology and chemical composition of the samples. The UV–Visible spectra exhibit blue shift in optical band gap for iron incorporated ZnO nanoparticles. The excitonic peak at 367 nm relating to near band edge emission has been obtained through luminescence spectrum. Dielectric and ferroelectric properties of the studied samples have shown the Debye relaxation and 9% Fe-doped ZnO possess the highest remnant polarization among all the nano-compounds. The Zn0.97Fe0.03O sample exhibits ferromagnetic hysteresis loop with a magnetic moment of 0.01 Bohr Magneton per Fe ion. The Arrot-Belov-Kouvel plot for the samples favour antiferromagnetic character suggesting canted antiferromagnetic order along an axis leading to a weak ferromagnetic moment in the Fe-doped ZnO samples.

Structural, optical and Mössbauer spectroscopic investigations on the environment of Fe in Fe-doped ZnO (Zn1-xFexO) ceramics synthesized by solution combustion method

A series of Fe-doped ZnO (Zn1-xFexO, x = 0, 0.01, 0.03, 0.05, 0.07 and 0.10) samples were synthesized by solution combustion synthesis method using metal nitrates as oxidizers and glycine as fuel. A spongy network-type microstructure is observed by the SEM micrographs of all the synthesized samples. For Fe concentration lower than 0.05 (x ≤ 0.05), formation of phase-pure wurtzite (hexagonal) structured Zn1-xFexO powder with P63mc space group was confirmed from the X-ray diffraction results. However, for x ≥ 0.07, precipitation of ZnFe2O4 impurity phase was observed. Hence, the solubility limit for Fe in ZnO lattice is about x = 0.05 for the samples synthesized by solution combustion method. Two quadruple doublets observed in the 57Fe-Mössbauer spectra for each of the samples suggest that paramagnetic Fe3+ cations occupy two different lattice sites in the ZnO structure; they are the substitutional sites (1) without distortion of the surrounding structure and (2) with distortion due to the defects present in the surrounding structure. In the DRS spectra, an Urbach-like tail was observed in the band gap region, indicating that Fe-doping in the ZnO lattice modifies the electronic structure and enhances the absorption of visible light. Furthermore, the Kubelka-Munk plots suggest the presence of two different local structures validating the Mössbauer results. We studied the photocatalytic degradation of methylene blue dye using these Fe doped ZnO samples as catalysts and the studies revealed that presence of Fe could lead to the formation of carbonaceous material on the surface of the solution combustion synthesized Zn1-xFexO samples. Overall, our results demonstrate the structural characteristics of Fe in Fe-doped ZnO samples synthesized by solution combustion method.

Ultrafast microwave-assisted hydrothermal synthesis and photocatalytic behaviour of ferroelectric Fe3+-doped BaTiO3 nanoparticles under simulated sunlight

We report on the synthesis of polycrystalline Fe-doped BaTiO3 ferroelectric nanopowder that exhibits high visible light photocatalytic activity. The ferroelectric Fe-doped BaTiO3 samples with nominal Fe contents ranging from 2 to 8 at% are prepared by fast microwave-assisted hydrothermal synthesis. All the doped ferroelectrics exhibit enhanced light harvesting properties due to the charge transfer center of Fe being associated to strong absorption in the visible region. Also, the bulk photovoltaic effect arising from net shift current in the non-centrosymmetric crystal, provides an additional driving force to charge carrier separation. While the best photocatalytic activity is obtained with the 2 at% Fe3+-doped BaTiO3 ferroelectric, the more heavily doped systems show a gradual decrease in photoactivity. In comparison to the undoped BaTiO3, all the Fe3+-doped systems show improved photocatalytic activity under similar experimental conditions. We invoke the iron-associated absorption for an enhanced charge carrier generation and the bulk photovoltaic effect, a property of non-centrosymmetric crystals, for an enhanced charge carrier separation and migration.

Unraveling the effects Mn-site doping on structural, magnetic and magnetotransport properties of Nd0.67Sr0.33Mn0.9T0.1O3 (T= Mn, Fe, Cr, Ni)

The present work reports the effects Mn site doping on the structural, magnetic and magnetotransport properties of Nd0.67Sr0.33Mn0.9T0.1O3, where T = Mn, Fe, Cr and Ni. Structural analysis based on Rietveld refinement confirms that the samples crystallize in orthorhombic structure with Pbnm space group. A detailed investigation on the FTIR spectra hints to the improved metallic character of Nd0.67Sr0.33Mn0.9Mn0.1O3 and Nd0.67Sr0.33Mn0.9Ni0.1O3 samples. Strong ferromagnetic character of Nd0.67Sr0.33Mn0.9Mn0.1O3 and Nd0.67Sr0.33Mn0.9Cr0.1O3 is revealed from ZFC-FC magnetization studies, while the Fe and Ni doped samples possess strong AFM ground state. An irreversible metamagnetic transition is discernible from the hysteresis curve of Nd0.67Sr0.33Mn0.9Fe0.1O3. Transport studies reveal a charge ordered state in Fe doped sample close to its spin glass transition temperature, Tg = 65 K. Nd0.67Sr0.33Mn0.9Mn0.1O3 behave like a typical double exchange material with nearly same TC and TP values, whereas for all other samples TP lie much below TC. Low resistive state materialized in a strong AFM material as observed in Nd0.67Sr0.33Mn0.9Ni0.1O3, is rarely observed in manganites. Colossal MR values exhibited by Fe and Ni doped samples are understood based on phase separation scenario of manganites. Large dissimilarities evident in the magnetic and electronic properties of the compounds, though the dopant ions possess nearly same ionic size, are attributed to differences in their electronic configuration. Resistivity behavior of samples in different temperature regimes are comprehended based on existing models of conduction.

Effect of Fe-doping and post annealing temperature on the structural and optical properties of MoO3 nanosheets

In this article, pure and 5 wt% Fe-doped h-MoO3 nanosheets have been successfully synthesized using a hydrothermal method and annealed the 5 wt% Fe-doped sample at 200 °C and 300 °C. The influence of Fe-doping and post annealing temperature on the structural, morphological, elemental, functional and optical properties of the developed nanosheets has been investigated by XRD, FESEM, EDS, FTIR and UV–Vis–NIR spectrophotometer, respectively. The XRD results revealed that all samples are polycrystalline in nature with no impurities, although, after Fe incorporation the phase transformation behavior observed from hexagonal to mixed phases (hexagonal and orthorhombic) and after annealing it showed identical diffraction patterns. Scherrer method, Williamson–Hall analysis and Halder–Wagner method were used to investigate the crystallite size, lattice strain and dislocation density of the samples. A deterioration of crystallinity is obtained in crystallite size after Fe doping, which signifies the incorporation of Fe inside the MoO3 lattice network. The crystallinity improves gradually with increasing annealing temperature. The lattice strain and dislocation density showed reverse trend to crystallite size. All samples consist almost entirely of densely packed and randomly oriented nanosheets with an average width of 100–150 nm and length of 1000–1800 nm, confirmed from FESEM images. The iron incorporation in the h-MoO3 matrix is confirmed by EDX analysis. The FTIR spectra reveal the information about formation and stability of phase. The optical band gap becomes narrow from 2.83 to 2.70 eV after Fe-doping and then widens from 2.70 to 2.79 eV with increasing annealing temperature up to 300 °C.

Facile synthesis of Fe-doped g-C3N4 for enhanced visible-light photocatalytic activity

Fe-doped graphitic carbon nitride (g-C3N4) materials were synthesized by one-step thermal condensation of iron nitrate nonahydrate (Fe(NO3)3·9H2O) and melamine as precursors. The morphology and crystal structure of the synthesized Fe-doped g-C3N4 samples were verified by XRD, SEM and FT-IR methods. The results reveal that iron species were well dispersed in the structure of g-C3N4 without changing the layered stacking structures, and might intercalate into the layer of g-C3N4 by coordinating to N atoms to form intercalation compounds, thereby affecting the energy band structure, enhancing visible light absorption and electrons–holes separation rate. Especially, the sample with 0.5 wt% Fe exhibited the highest activity in degradation of Rhodamine B under visible light irradiation, indicating that Fe doping could promote the photocatalytic activity of g-C3N4, while excessive Fe might break the sheet structure and inhibit activity. A plausible mechanism for the enhanced photocatalytic activity was proposed from trapping experiments, which emphasized the pivotal role of Fe3+/Fe2+ couple in the photocatalytic reaction.

Change nonlinear-optical response of electro-optic crystal in conditions of contributions incoherent background illumination

Influence of incoherent background on diffraction divergence of narrow light beams of He-Ne laser with wavelength of 633 nm due to refractive index changes of Fe-doped lithium niobate sample is experimentally studied. Incoherent background is produced by light-emitting diodes (LED´s) of different average wavelengths and laser diode emitting in blue region of visible. It has been experimentally demonstrated that nonlinear diffraction of coherent red beams of He-Ne laser with diameters on full width of half maximum (FWHM) near to 15–20 μm may be totally compensated by means of assistance of incoherent background with shorter average wavelengths 455–465 nm and even much lower intensity compared with that for coherent beam.

Sodium dodecyl sulfate mediated microwave synthesis of biocompatible superparamagnetic mesoporous hydroxyapatite nanoparticles using black Chlamys varia seashell as a calcium source for biomedical applications

Abstract Designing biocompatible superparamagnetic mesoporous nanoparticles for advanced healthcare applications has received much attention. In this research, we have synthesized intrinsic mesoporous superparamagnetic hydroxyapatite (HAp) nanoparticles using bio-waste of black Chlamys varia seashell as a calcium source by sodium dodecyl sulfate (SDS)–enabled microwave-assisted synthesis approach. The synthesized Fe-doped HAp nanoparticles were characterized using various characterization techniques to know the phase purity and morphological features. The incorporation of Fe greatly affected the morphology of HAp nanoparticles without affecting their crystalline phase. Superparamagnetic behavior was observed with the incorporation of Fe in the HAp nanoparticles. Further, saturation magnetization was enhanced with higher incorporation of Fe ions. The cytotoxicity studies of the synthesized pure and Fe-doped HAp samples conducted using a human osteoblasts cell line (MG63), which indicated that Fe-doped HAp nanoparticles are biocompatible. Further, antibacterial activity analysis also confirmed their excellent antibacterial performance against different pathogens. Hence, SDS-enabled microwave-assisted synthesis approach using seashell as a calcium source would be a better approach for the production of intrinsic mesoporous superparamagnetic HAp nanoparticles for various biomedical applications, such as drug targeting, hyperthermia cancer therapy, and magnetic resonance imaging.

Influence of Fe doping on the structural, optical and thermal properties of α-MnO2 nanowires

We report the synthesis of pure and Fe-doped α-MnO2 nanowires by a facile hydrothermal method. The influence of iron with varying doping concentration on structural, optical and thermal properties of crystalline α-MnO2 nanowires is discussed. X-ray diffraction studies indicate that the synthesized nanowires have tetragonal structure and are in crystalline α-MnO2 phase with average crystallites size of 17.36 nm for pure α-MnO2 while 14.59 nm, 14.93 nm and 13.32 nm for 5 mol %, 10 mol % and 15 mol % Fe-doped α-MnO2, respectively. Scanning electron microscopy images show that the synthesized products have nanowire morphology with an average diameter of 38 nm for pure α-MnO2 and 28 nm for 5 mol % Fe-doped α-MnO2. In Fourier transform infrared spectra, the strong absorption band at 501 cm−1 and 699 cm−1 correspond to the bending and stretching vibration of Mn–O bond. Furthermore, Thermal gravimetric analysis indicates that Fe doping in MnO2 leads to the enhancement of its thermal stability. The broad absorption band of the UV–vis spectra appeared at 250 nm to 600 nm for pure α-MnO2 and at 250 nm to 700 nm for Fe-doped α-MnO2 nanowires is assigned to the d-d transition between lower t2g and higher eg of the metallic ions. For the first time we are reporting an indirect optical bandgap energy of 0.30 eV, 0.29 eV and 0.18 eV for different Fe-doped α-MnO2 samples.

Effects of transition metal dopants on the calcination of CaCO3 under Ar, H2O and H2

This study compares thermal decomposition of pure and transition metal-doped (Fe, Co, Ni, Cu, and Zn) calcium carbonate samples under ˜0.1 mbar of Ar, H2O, and H2 in order to evaluate the effects of doping on CO2 release and conversion. All samples were synthesized via precipitation methods at room temperature from calcium chloride and sodium carbonate precursors, with additional doping of the relevant transition metal chloride. Structural and compositional analysis of the as-prepared and calcined materials is presented. TM-doping results in an earlier onset of CO2 release as compared to Pure CaCO3 irrespective of calcination gas. Cu-doping induced the largest temperature reduction. Calcination in H2O produces an additional lowering of the release temperature, as compared with calcination in Ar, with the Zn-doped sample exhibiting the largest enhancement. During calcination in H2, the Ni-, Co- and Fe-doped samples produce a significant enhancement of CO2 to CO conversion, whereas the overall conversion by the Cu- and Zn-doped samples remained comparable to that of Pure CaCO3. The Ni-doped samples, which produced the highest CO2 conversion, showed the largest comparative enhancement when the calcination gas was changed to H2.

Investigation of Fe-doped room temperature dilute magnetic ZnO semiconductors

Different ceramics sample of Zn1−xFexO (ZFO) series have been sintered by solid state reaction method. Single phase polycrystalline Fe-doped ZnO sample with hexagonal wurtzite structure has been obtained with x<0.03 mol. Segregation of Fe and/or its oxides have not been found in the XRD patterns. A weak secondary phase of ZnFe2O4 has been detected with x⩾0.03 mol. Presence of Ohmic conductivity has been detected in the dielectric property analysis and the reasons for this Maxwell-Wagner-Sillars (MWS) relaxation has been explained by the grain boundary barrier defect (GBBD) process. The obtained shift of diamagnetic behavior of pure ZnO samples to para-magnetic for ZFO samples has been established with the defect and impurity structure. The band gap energy for ZFO samples has been calculated between 2.85eV to 3.15eV. The results indicate the potential use of Fe doped ZnO ceramics in high frequency device applications.

Understanding structural, optical, magnetic and electrical performances of Fe- or Co-substituted spinel LiMn1.5Ni0.5O4 cathode materials

Spinel LiMn1.5Ni0.5O4 (LNMO) and LiMn1.5Ni0.25M0.25O4(M=Co (LNCMO) or Fe LNFMO) have been purposefully tailored using a sol–gel auto-combustion method at low annealing temperature. Well crystalline disordered spinel Fd3m structure was formed. The particles of LNMO sample evinced a regular octahedron shape-like morphology with wide particle size distribution from 42 to 82 nm. However, the Co- and Fe-doped LNMO samples were obtained from larger and flattened particles with lower facets particles and narrower particle size distribution (55–80 nm). EDX spectroscopy confirmed the elemental analysis were uniformly distributed in the samples. The band gap was found to decrease with Co3+ and Fe3+ ion substitution, indicating a shortening in the distance between the valence and the conduction bands. The magnetic properties indicated weak ferromagnetic performance. EIS spectra evidenced that a typical semicircle was revealed for each cell, suggesting the absence of ionic conductivity contribution. The values of charge transfer resistance (Rct) were equal to 16.1, 3.4 and 9.3 kΩ for the LNMO, LNCMO and LNFMO cells, respectively. The AC conductivity measurements showed a faster kinetic rate and lower activation energy of conduction for LiNi0.25Co0.25Mn1.5O4.

Near infrared emission and enhanced ferromagnetism in Fe doped SrSnO3 perovskite structured nanorods

SrSn1−xFexO3 (x = 0, 0.01, 0.03 and 0.05) nanorods prepared by chemical precipitation method was investigated for the effect of Fe doping on structural, optical and magnetic properties. X-ray diffraction pattern of the prepared samples indicated orthorhombic structure with considerable variation in the lattice parameters, confirming the Fe incorporation in Sr–Sn–O lattice. Electron microscopy studies revealed the surface morphology changes from rods with poly-dispersed particles to well-defined rod shapes, upon Fe doping. FTIR, Raman, X-ray photoelectron and UV–Vis spectroscopy results confirmed the presence of metal oxide vibrations, active Raman modes, oxygen vacancy and strong optical absorption, respectively. Photoluminescence studies showed an interesting feature of near-infrared emission for the Fe doped samples. Magnetization measurements at room temperature demonstrated dia- to ferro- magnetic phase transition as a result of increased Fe concentration. Fe 5% doped sample significantly exhibited an increased coercivity with a maximum at 2 K. The induced ferromagnetic behavior and near infrared emission in Fe doped SrSnO3 suggest the material for magneto-electronic device applications.

Vortex dynamics behavior with third harmonic ac-susceptibility for nano Fe-doped MgB2 superconductor

In the present study, the nano Fe-doped MgB2 samples with different doping contents (0 wt% ≤ x ≤ 6 wt%) were synthesized by the solid-state reaction technique. The fundamental and third harmonic real and imaginary components of ac-susceptibility were measured with an ac-applied field of Hac = 0.5 Oe under the different frequency range f = 1–3 kHz. The amplitude of the peaks in the first harmonic imaginary component as a function of temperature, $${\chi ^{\prime\prime}_1}(T)$$ plots enhances regularly as we increase the frequency and shifted towards the higher temperature region. The highest amplitude of the peak is shown by 3 wt% doped sample among the undoped and doped sample in $${\chi ^{\prime\prime}_1}(T)$$ plot. The χ3″ reveals the sinusoidal oscillation with maxima and minima of the ratio δ, a parameter associated with the penetration depth of the ac-applied field. The amplitude of the real component χ3′ is smaller than the imaginary component of χ3″ in third harmonic ac-susceptibility measurements. The 6 wt% nano-Fe doped MgB2 sample shows the multiple real and imaginary peaks of third harmonic ac-susceptibility, χ3. The irreversibility line (IL) is shifted towards the higher temperature site with the increases of frequency. The slope of the IL increases with the increase of frequency.

Ferromagnetic order in substitutional Fe-doped In2O3 powder

We report an experimental investigation of the room-temperature ferromagnetism of an Fe-doped In2O3 system. (In1−xFex)2O3(x = 0.00, 0.02, 0.06,0.10,0.14 or 0.18) powders were prepared by a standard solid-state reaction method followed by sintering in air at 1200 °C for 48 h. The influence of Fe-doping concentration on the structural and magnetic properties of the In2O3 samples was studied. X-ray diffraction analysis reveals that Fe ions are incorporated into the In3+ sites of the In2O3 lattice without altering the cubic bixbyite structure. Magnetic characterization shows ferromagnetic behavior at room temperature for all the Fe-doped In2O3 samples. The observed ferromagnetism is attributed to the oxygen vacancies induced by substitution of Fe into In3+ sites and vacuum annealing. A model of ferromagnetic exchange interactions was proposed to explain the ferromagnetism in this system.