Selective fabrication of metastable greigite (Fe3S4) nanocrystallites and its magnetic properties through a simple solution-based route

Chen, Xiangying; Zhang, Xingfa; Wan, Jiamin; Wang, Zhenghua; Qian, Yitai

doi:10.1016/j.cplett.2005.01.050

Cited by 41 publications

(20 citation statements)

References 14 publications

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“…The divergence of the field cooling (FC) and zero field cooling (ZFC) data (even at 240 K) indicate the formation of an ordered magnetic state, which may be due to the high Curie temperature of the sample. [53] The field dependence of the magnetization curve of Fe 7 Se 8 polyhedra measured at 300 K (Figure 9 b), which exhibits a hysteresis with remanent magnetization (M r ) of 0.14 emu g À1 and coercive field (H c ) of 533 Oe, further reveals a weak ferromagnetism in the sample that is in accordance with the results of FC and ZFC data. It is now well accepted that the magnetic properties of materials are sensitive to their composition, morphology, surface condition, and strain.…”

Section: Resultssupporting

confidence: 84%

Selective Synthesis of Fe₇Se₈ Polyhedra with Exposed High‐Index Facets and Fe₇Se₈ Nanorods by a Solvothermal Process in a Binary Solution and Their Collective Intrinsic Properties

Gao

Lin

Jiang

et al. 2011

Chemistry A European J

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Fe(7)Se(8) polyhedra with high-index facets and Fe(7)Se(8) nanorods can be selectively synthesized by a solvothermal reaction in a mixed solvent of diethylenetriamine (DETA) and deionized water (DIW). It is found that the morphologies of Fe(7)Se(8) nanocrystals can be effectively controlled by adjusting the volume ratio of DETA and DIW. The unusual polyhedral crystals are bounded by two {001} and twelve {012} facets. The intrinsic properties of Fe(7)Se(8) nanocrystals have been investigated. Magnetic measurements indicate that the obtained polyhedra and nanorods show a weak ferromagnetic ordering at room temperature. In particular, a new photoluminescence emission at 403 nm from the Fe(7)Se(8) nanocrystals has been observed. The described solvothermal reaction in a mixed solvent may be extended to the synthesis of other transition-metal chalcogenide crystals with controlled shape, facets, and structure, which may bring new functionalities.

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Section: Resultssupporting

confidence: 84%

Selective Synthesis of Fe₇Se₈ Polyhedra with Exposed High‐Index Facets and Fe₇Se₈ Nanorods by a Solvothermal Process in a Binary Solution and Their Collective Intrinsic Properties

Gao

Lin

Jiang

et al. 2011

Chemistry A European J

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“…Co 9 S 8 and CoS 2 were selectively fabricated by the reaction of cobalt chlorides and sodium polysulfide via a toluene thermal process [12]; CoS was obtained from amorphous cobalt sulfide in hydrazine solution at 120 • C [13]. Meanwhile, we have previously synthesized Ni 3 S 4 [14] and Fe 3 S 4 [15] nanocrystallites with the analogous spinel structure to Co 3 S 4 through the solution-phase approach. However, to the best of our knowledge, there are few reports on the synthesis of Co 3 S 4 nanocrystallites, especially 1D nanotubes, under mild conditions.…”

Section: Introductionmentioning

confidence: 99%

Hydrothermal fabrication and characterization of polycrystalline linneite (Co3S4) nanotubes based on the Kirkendall effect

Chen

Zhang

Qiu

et al. 2007

Journal of Colloid and Interface Science

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“…FeS slurries were precipitated following the methods of Chen et al (2005). In brief, 100 ml of 0.3 M Fe 2 + solution (prepared from FeSO 4 ⁎ 7H 2 O) was mixed with 100 ml of 0.52 M thioacetamide solution (C 2 H 5 NS) in a beaker on a magnetic stirrer.…”

Section: Synthesis Of Fesmentioning

confidence: 99%

Structural properties and transformations of precipitated FeS

et al. 2012

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Editor: J. Fein Keywords:Amorphous iron sulfide Mackinawite Greigite Phase transformations XRD TEM Nanocrystalline iron sulfides form in diverse anoxic environments. The initial precipitate is commonly referred to as nanocrystalline mackinawite (FeS) or amorphous FeS. In order to better understand the structure of the initial precipitate and its conversion to mackinawite and greigite (Fe 3 S 4 ), we studied synthetic iron sulfide samples that were precipitated from hydrous solutions near room temperature. The transformation of precipitated FeS was followed in both aqueous and dry aging experiments using X-ray powder diffraction (XRD) and scanning and transmission electron microscopy (SEM/TEM) and selected-area electron diffraction (SAED). Under tightly controlled anoxic conditions the first precipitate was nanocrystalline mackinawite. In contrast, when anaerobic conditions during synthesis were not completely ensured, freshly precipitated iron sulfide was typically X-ray amorphous (FeS am ), and showed only one broad Bragg-peak at 2Θ = 16.5°(5.4 Å). A distribution of interatomic distances calculated from pair-distribution function analysis of SAED patterns of FeS am showed that only short-range (b 7 Å) order was present in the bulk of the material, with Fe mainly present in tetrahedral coordination. SEM and TEM images confirmed the poorly ordered structure and showed that FeS am formed aggregates of curved, amorphous sheets that contained 3-8 structurally ordered layers at their cores. Such layers are generally assumed to be structurally similar to the tetrahedral iron sulfide layers in mackinawite. However, both inter-and intralayer spacings measured in high-resolution TEM images (~5.3 to 6.3 and~3.0 to 3.1 Å, respectively) were significantly larger than the corresponding spacings in crystalline mackinawite (5.03 and 2.6 Å, respectively), suggesting that short-range structural order within the semi-ordered layers of FeS am was not mackinawite-like. In aqueous aging experiments at room temperature, FeS am transformed into a mixture of mackinawite and greigite in~2 months, and completely converted to platy greigite crystals after~10 months. These aqueous transformations were likely driven by excess sulfur in the reacting solutions. We also studied the conversions of nanocrystalline mackinawite. In order to accelerate phase transitions, the initial FeS precipitate was heated to 120°C, resulting in the formation of crystalline mackinawite within 2 h; at 150°C, the material converted directly to pyrrhotite. Finally, when stored in a dry state at room temperature, crystalline mackinawite converted to greigite in 3 months, much faster than in the equivalent experiments in the aqueous solution, probably as a result of a more oxidative environment. The distinction between FeS am and nanocrystalline mackinawite is significant, since conditions for the formation of both phases are present in natural settings. Our experiments in a well-sealed anaerobic chamber simulate iron sulfide formation under anoxic conditions, where...

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Selective fabrication of metastable greigite (Fe3S4) nanocrystallites and its magnetic properties through a simple solution-based route

Cited by 41 publications

References 14 publications

Selective Synthesis of Fe₇Se₈ Polyhedra with Exposed High‐Index Facets and Fe₇Se₈ Nanorods by a Solvothermal Process in a Binary Solution and Their Collective Intrinsic Properties

Selective Synthesis of Fe₇Se₈ Polyhedra with Exposed High‐Index Facets and Fe₇Se₈ Nanorods by a Solvothermal Process in a Binary Solution and Their Collective Intrinsic Properties

Hydrothermal fabrication and characterization of polycrystalline linneite (Co3S4) nanotubes based on the Kirkendall effect

Structural properties and transformations of precipitated FeS

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Selective fabrication of metastable greigite (Fe3S4) nanocrystallites and its magnetic properties through a simple solution-based route

Cited by 41 publications

References 14 publications

Selective Synthesis of Fe7Se8 Polyhedra with Exposed High‐Index Facets and Fe7Se8 Nanorods by a Solvothermal Process in a Binary Solution and Their Collective Intrinsic Properties

Selective Synthesis of Fe7Se8 Polyhedra with Exposed High‐Index Facets and Fe7Se8 Nanorods by a Solvothermal Process in a Binary Solution and Their Collective Intrinsic Properties

Hydrothermal fabrication and characterization of polycrystalline linneite (Co3S4) nanotubes based on the Kirkendall effect

Structural properties and transformations of precipitated FeS

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Selective Synthesis of Fe₇Se₈ Polyhedra with Exposed High‐Index Facets and Fe₇Se₈ Nanorods by a Solvothermal Process in a Binary Solution and Their Collective Intrinsic Properties

Selective Synthesis of Fe₇Se₈ Polyhedra with Exposed High‐Index Facets and Fe₇Se₈ Nanorods by a Solvothermal Process in a Binary Solution and Their Collective Intrinsic Properties