Names | |
---|---|
IUPAC name
Iron(II) selenide
| |
Identifiers | |
3D model (
JSmol)
|
|
ECHA InfoCard | 100.013.798 |
EC Number |
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PubChem
CID
|
|
UNII | |
CompTox Dashboard (
EPA)
|
|
| |
| |
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
|
toxic |
Related compounds | |
Other
anions
|
Iron(II) oxide Iron(II) sulfide Iron(II) telluride |
Other
cations
|
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).
|
Iron(II) selenide refers to a number of inorganic compounds of ferrous iron and selenide (Se2−). The phase diagram of the system Fe–Se [1] reveals the existence of several non-stoichiometric phases between ~49 at. % Se and ~53 at. % Fe, and temperatures up to ~450 °C. The low temperature stable phases are the tetragonal PbO-structure (P4/nmm) β-Fe1−xSe and α-Fe7Se8. The high temperature phase is the hexagonal, NiAs structure (P63/mmc) δ-Fe1−xSe. Iron(II) selenide occurs naturally as the NiAs-structure mineral achavalite.
More selenium rich iron selenide phases are the γ phases (γ and γˈ), assigned the Fe3Se4 stoichiometry, and FeSe2, which occurs as the marcasite-structure natural mineral ferroselite, or the rare pyrite-structure mineral dzharkenite.
It is used in electrical semiconductors.[ citation needed]
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]
Names | |
---|---|
IUPAC name
Iron(II) selenide
| |
Identifiers | |
3D model (
JSmol)
|
|
ECHA InfoCard | 100.013.798 |
EC Number |
|
PubChem
CID
|
|
UNII | |
CompTox Dashboard (
EPA)
|
|
| |
| |
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
|
toxic |
Related compounds | |
Other
anions
|
Iron(II) oxide Iron(II) sulfide Iron(II) telluride |
Other
cations
|
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).
|
Iron(II) selenide refers to a number of inorganic compounds of ferrous iron and selenide (Se2−). The phase diagram of the system Fe–Se [1] reveals the existence of several non-stoichiometric phases between ~49 at. % Se and ~53 at. % Fe, and temperatures up to ~450 °C. The low temperature stable phases are the tetragonal PbO-structure (P4/nmm) β-Fe1−xSe and α-Fe7Se8. The high temperature phase is the hexagonal, NiAs structure (P63/mmc) δ-Fe1−xSe. Iron(II) selenide occurs naturally as the NiAs-structure mineral achavalite.
More selenium rich iron selenide phases are the γ phases (γ and γˈ), assigned the Fe3Se4 stoichiometry, and FeSe2, which occurs as the marcasite-structure natural mineral ferroselite, or the rare pyrite-structure mineral dzharkenite.
It is used in electrical semiconductors.[ citation needed]
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]