Chemistry:Chromium(II) selenide

From HandWiki
Chromium(II) selenide
Names
IUPAC name
Chromium(2+) selenide
Identifiers
3D model (JSmol)
EC Number
  • 234-999-1
Properties
CrSe
Molar mass 130.96 g/mol
Appearance white to pale yellow crystalline powder
Density 6.74 g/cm3
Melting point ~1500 °C
insoluble
Structure[1]
NiAs type (hexagonal)
P63/mmc, No. 194
a = 371 pm, c = 603 pm
Hazards
NFPA 704 (fire diamond)
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilHealth code 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineReactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no codeNFPA 704 four-colored diamond
1
1
1
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 1 mg/m3[2]
REL (Recommended)
TWA 0.5 mg/m3[2]
IDLH (Immediate danger)
250 mg/m3[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Chromium(II) selenide is an inorganic compound with the chemical formula CrSe. It crystalizes in a hexagonal structure with space group P63/mmc.[3] It is one of many related Chromium-Selenium phases, including Cr7Se8, Cr3Se4, Cr0.68Se, Cr2Se3, and Cr5Se8.[3] The compound has been described as an antiferromagnet, but its inverse magnetic susceptibility does not match the behavior expected for an antiferromagnet according to the Curie–Weiss law.[1] One suggestion was that the Néel temperature is at 320 K, as the temperature where the compound has maximum specific heat.[4] When synthesized as single atomic layer, CrSe is ferromagnetic, with a Curie Temperature of around 280 K.[5]

References

  1. 1.0 1.1 Lotgering, F.K.; Gorter, E.W. (1957). "Solid solutions between ferromagnetic and antiferromagnetic compounds with NiAs structure". Journal of Physics and Chemistry of Solids (Elsevier BV) 3 (3-4): 238–249. doi:10.1016/0022-3697(57)90028-8. ISSN 0022-3697. 
  2. 2.0 2.1 2.2 NIOSH Pocket Guide to Chemical Hazards. "#0141". National Institute for Occupational Safety and Health (NIOSH). https://www.cdc.gov/niosh/npg/npgd0141.html. 
  3. 3.0 3.1 Wehmeier, F. H.; Keve, E. T.; Abrahams, S. C. (1970). "Preparation, structure, and properties of some chromium selenides. Crystal growth with selenium vapor as a novel transport agent". Inorganic Chemistry (American Chemical Society (ACS)) 9 (9): 2125–2131. doi:10.1021/ic50091a032. ISSN 0020-1669. 
  4. Tsubokawa, Ichiro (1960). "The Magnetic Properties of Single Crystals of Chromium Selenide". Journal of the Physical Society of Japan (Physical Society of Japan) 15 (12): 2243–2247. doi:10.1143/jpsj.15.2243. ISSN 0031-9015. 
  5. Zhang, Yu; Chu, Junwei; Yin, Lei et al. (2019-03-28). "Ultrathin Magnetic 2D Single‐Crystal CrSe". Advanced Materials (Wiley) 31 (19): 1900056. doi:10.1002/adma.201900056. ISSN 0935-9648.