Magnetic properties of iron marcasite FeS2

We report that a solid‐state battery architecture enables the reversible, four electron storage of fully utilized solvothermally synthesized cubic‐FeS2 (pyrite). With a sulfide based glass electrolyte we successfully confine electro‐active species and permit the safe use of a lithium metal anode. These FeS2/Li solid‐state cells deliver a theoretical specific capacity of 894 mAh g−1 at 60 °C. We find that nanoparticles of orthorhombic‐FeS2 (marcasite) are generated upon recharge at 30–60 °C which explains a coincident change in rate kinetics.

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“…[ 4 ] And finally, orthorhombic-FeS 2 exhibits very weak temperature independent paramagnetism. [ 26 ] …”

Section: Discussionmentioning

confidence: 97%

Solid State Enabled Reversible Four Electron Storage

Yersak¹,

Macpherson²,

Kim³

et al. 2012

Advanced Energy Materials

171

230

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“…4(b) we show the temperature dependent magnetic susceptibility M(T) between T ¼ 10 and 300 K in an external magnetic eld of m 0 H ¼ 1 T. The inset shows the elddependent magnetic measurements M(H) at temperatures of T ¼ 300 K. The magnetic susceptibility of marcasite single crystal is found to be nearly temperature independent and diamagnetic, which is in good agreement with theoretical predictions but has never been experimentally shown on previous investigations. 39 At very low temperature T < 10 K, we nd a so-called Curie-tale, which is caused by tiny magnetic impurities, as expected for any material. The iron in marcasite is in the oxidation state Fe(II) in a d 6 conguration, hence the magnetic groundstate is a low-spin state with all the t 2g orbitals fully occupied and the e g orbitals empty.…”

Section: Physical Properties Of Laboratory Prepared Fes 2 Marcasite Single Crystalsmentioning

confidence: 80%

“…sulphur vacancies) and other impurities. 32,33,39 Here, based on the laboratory prepared high-quality marcasite single crystals, we systematically measured its fundamental physical properties and compared them with previous measurement results on natural mineral samples.…”

Section: Physical Properties Of Laboratory Prepared Fes 2 Marcasite Single Crystalsmentioning

confidence: 99%

Synthetic control over polymorph formation in the d-band semiconductor system FeS₂

Lefèvre

et al. 2021

Chem. Sci.

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“…However, those samples have substantial structure deficits (e.g. sulphur vacancies) and other impurities 32,33,39 . Here, based on the laboratory prepared high-quality marcasite single crystals, we systematically measured its fundamental physical properties and compared them with previous measurement results on natural mineral samples.…”

Section: Physical Properties Of Laboratory Prepared Fes 2 Marcasite S...mentioning

confidence: 99%

Synthetic control over polymorph formation in the d-band semiconductor system FeS$_2$

Ma,

Lefèvre,

et al. 2021

Preprint

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Pyrite, also known as fool's gold is the thermodynamic stable polymorph of FeS 2 . It is widely considered as a promising d-band semiconductor for various applications due to its intriguing physical properties. Marcasite is the other naturally occurring polymorph of FeS 2 . Measurements on natural crystals have shown that it has similarly promising electronic, mechanical, and optical properties as pyrite. However, it has been only scarcely investigated so far, because the laboratory-based synthesis of phase-pure samples or high quality marcasite single crystal has been a challenge until now. Here, we report the targeted phase formation via hydrothermal synthesis of marcasite and pyrite. The formation condition and phase purity of the FeS 2 polymorphs are systematically studied in the form of a comprehensive synthesis map. We, furthermore, report on a detailed analysis of marcasite single crystal growth by a space-separated hydrothermal synthesis. We observe that single phase product of marcasite forms only on the surface under the invovlement of H 2 S and sulphur vapor. The availability of high-quality crystals of marcasite allows us to measure the fundamental physical properties, including an allowed direct optical bandgap of 0.76 eV, temperature independent diamagnetism, an electronic transport gap of 0.11 eV, and a room-temperature carrier concentration of 4.14 × 10 18 cm −3 . X-ray absorption/emission spectroscopy are employed to measure the band gap of the two FeS 2 phases. We find marcasite has a band gap of 0.73 eV, while pyrite has a band gap of 0.87 eV. Our results indicate that marcasite -that is now synthetically available in a straightforward fashion -is as equally promising as pyrite as candidate for various semiconductor applications based on earth abundant elements.

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Magnetic properties of iron marcasite FeS2

Cited by 10 publications

References 9 publications

Solid State Enabled Reversible Four Electron Storage

Solid State Enabled Reversible Four Electron Storage

Synthetic control over polymorph formation in the d-band semiconductor system FeS₂

Synthetic control over polymorph formation in the d-band semiconductor system FeS$_2$

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Magnetic properties of iron marcasite FeS2

Cited by 10 publications

References 9 publications

Solid State Enabled Reversible Four Electron Storage

Solid State Enabled Reversible Four Electron Storage

Synthetic control over polymorph formation in the d-band semiconductor system FeS2

Synthetic control over polymorph formation in the d-band semiconductor system FeS$_2$

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Synthetic control over polymorph formation in the d-band semiconductor system FeS₂