Large-scale synthesis of mixed valence K3[Fe2S4] with high dielectric and ferrimagnetic characteristics

Ghazanfari, Mohammad Reza; Santhosh, Archa; Vrijmoed, Johannes C.; Siemensmeyer, Konrad; Peters, Bertram; Dehnen, Stefanie; Jerabek, Paul; Thiele, Günther

doi:10.1039/d2ra05200h

Cited by 3 publications

(1 citation statement)

References 50 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Sie haben das ferrimagnetische K 3 [Fe 2 S 4 ] phasenrein hergestellt, und zwar aus den Edukten Schwefel, K 2 S und FeS in 5 Minuten bei 1200 °C in einer Silica-Ampulle. 40) Neben Konzentration und Temperatur ist ein grundlegender Reaktionsparameter der Druck. Dessen Veränderung führt bisweilen zu unbekannten Verbindungen.…”

Section: Neue Strukturen Und Verbindungenunclassified

Trendbericht Festkörperchemie und Materialforschung 2024

Rasche,

Schwartz

2024

Nachr Chem

View full text Add to dashboard Cite

Schwerpunkte sind die Effizienz von Synthesen, deren Nachhaltigkeit oder Materialien für eine CO2‐emissionsärmere Zukunft. Neben der gesellschaftlichen Dringlichkeit, hervorgerufen durch den Klimawandel, ist dieser Umschwung dadurch motiviert, dass Drittmittel vor allem für Anwendungsforschung vergeben werden. Bei dieser lösungsorientierten Festkörperforschung verschmelzen klassische Chemie, Physik und Materialwissenschaften. Dennoch bleiben Grundlagenthemen essenziell.

show abstract

Section: Neue Strukturen Und Verbindungenunclassified

Trendbericht Festkörperchemie und Materialforschung 2024

Rasche,

Schwartz

2024

Nachr Chem

View full text Add to dashboard Cite

show abstract

Semiconducting Mixed Valence Sulfido (Selenido) Ferrates: Optical, Dielectric, and Electrochemical Impedance Properties

Reza Ghazanfari,

Janus,

Ramadan

et al. 2024

Eur J Inorg Chem

View full text Add to dashboard Cite

The ternary potassium sulfido and selenido ferrates K9[Fe2S(e)7] were synthesized as pure phases through a facile and straightforward solid‐state method. The compounds crystalize isotypic as has been reported previously. UV‐visible measurements indicate semiconductivity, showing direct optical band gaps with energies of 1.91 eV for the sulfido and 1.72 eV for the selenido ferrate. Investigations of dielectric and impedance properties provide their dielectric constants in the range of 60 to 74 at room temperature at a frequency of 1 kHz, as well as ionic conductivity values in the range of 2.08∙10–5 and 2.61∙10–5 mS·cm–1. Both, the dielectric constants and the calculated ionic conductivity of the selenido ferrate are higher compared to the sulfido ferrate, corresponding to the larger unit cell volume and increased bond lengths in the selenido ferrates. The dielectric constants are comparably higher than the reference material of SiO2, which might introduce them for dielectric applications.

show abstract

Structural, optical and giant dielectric constant properties of pure ktenasite and schulenbergite/CuO minerals

Yakout

Youssef

Mousa

2023

J Mater Sci: Mater Electron

View full text Add to dashboard Cite

In this study, schulenbergite [(Cu,Zn)7(SO4)2(OH)10·3H2O)]/CuO and pure ktenasite [(Cu,Zn)5(SO4)2(OH)6·6H2O)] minerals were simply synthesized via addition of sodium sulfide (Na2S) to a mixture of nanosized CuO powder dispersed into Zn(NO3)2·6H2O solution. The X-ray diffraction patterns illustrate the formation of schulenbergite/CuO mineral with ratio of 69:31% and 87/13% owing to additions of 0.1 and 0.2 mol L−1 Na2S, respectively. The addition of 0.4 mol L−1 Na2S substance lead to formation of pure ktenasite [(Cu,Zn)5(SO4)2(OH)6·6H2O)] mineral. The absorption vibration modes based on Fourier-transform infrared (FTIR) analysis verified the formation of schulenbergite/CuO and pure ktenasite compositions. The scanning electron microscope micrographs of schulenbergite/CuO and pure ktenasite samples reveal the formation of mixed grains with needle, sheets, cotton and wool shapes. The selected area electron diffraction images of the synthesized powders show strong dot-rings, indicating polycrystalline nature. Optically, all samples possess a high absorption ability for infrared-visible light wavelengths. At lower frequencies, the pellet of pure ktenasite sample exhibits giant dielectric constant characteristics. Exactly, pure ktenasite sample reveals a dielectric constant value of ~ 1.3 × 106 at frequency of 42 Hz. For schulenbergite/CuO (87/13%) sample, a large dielectric constant value of ~ 5311 was measured at frequency of 42 Hz. The colossal and variable relative permittivity values make the pure ktenasite [(Cu,Zn)5(SO4)2(OH)6·6H2O)] mineral is a suggested material for energy storage applications.

show abstract

Large-scale synthesis of mixed valence K₃[Fe₂S₄] with high dielectric and ferrimagnetic characteristics

Abstract: Large scale, high purity synthesis of K3[Fe2S4] which indicates soft ferrimagnetic, high dielectric and semiconductive characteristics.

Cited by 3 publications

References 50 publications

Trendbericht Festkörperchemie und Materialforschung 2024

Trendbericht Festkörperchemie und Materialforschung 2024

Semiconducting Mixed Valence Sulfido (Selenido) Ferrates: Optical, Dielectric, and Electrochemical Impedance Properties

Structural, optical and giant dielectric constant properties of pure ktenasite and schulenbergite/CuO minerals

Contact Info

Product

Resources

About