Iron(II) selenide
| Names | |
|---|---|
| IUPAC name
Iron(II) selenide
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| Identifiers | |
3D model (
JSmol ) |
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ECHA InfoCard
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100.013.798 |
| EC Number |
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PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| FeSe | |
| Molar mass | 134.807 g/mol |
| Appearance | black crystals |
| Density | 4.72 g/cm3 |
| Melting point | 965 °C (1,769 °F; 1,238 K) |
| 0.975 mg/100mL[citation needed] | |
| Structure | |
| hexagonal / tetragonal | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
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toxic |
| Related compounds | |
Other anions
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Iron(II) oxide Iron(II) sulfide Iron(II) telluride |
Other cations
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Manganese(II) selenide Cobalt(II) selenide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Iron(II) selenide refers to a number of
achavalite
.
More selenium rich iron selenide phases are the γ phases (γ and γˈ), assigned the Fe3Se4
dzharkenite
.
It is used in electrical semiconductors.[citation needed]
Superconductivity
β-FeSe is the simplest iron-based superconductor but with diverse properties.[2] It starts to superconduct at 8 K at normal pressure[3] but its critical temperature (Tc) is dramatically increased to 38 K under pressure,[4] by means of intercalation,[2] or after quenching at high pressures.[5] The combination of both intercalation and pressure results in re-emerging superconductivity at 48 K.[2]
In 2013 it was reported that a single atomic layer of FeSe
epitaxially grown on SrTiO3 is superconductive with a then-record transition temperature for iron-based superconductors of 70 K.[6] This discovery has attracted significant attention and in 2014 a superconducting transition temperature of over 100K was reported for this system.[7]