Strontium disilicide

Names
Other names Strontium silicide, strontium(II) silicide
Identifiers
CAS Number	12138-28-2 Y
3D model (JSmol)	Interactive image
ChemSpider	95796049
ECHA InfoCard	100.032.031
EC Number	235-248-0
PubChem CID	138395194
CompTox Dashboard (EPA)	DTXSID301014285
InChI InChI=1S/2Si.Sr/q2*-1;+2 Key: DXKAKWDPPFFMSM-UHFFFAOYSA-N
SMILES [Si-].[Si-].[Sr+2]
Properties
Chemical formula	Si2Sr
Molar mass	143.79 g·mol−1
Appearance	silver-gray crystals[1]
Density	3.35 g/cm3
Melting point	1,100 °C (2,010 °F; 1,370 K)
Solubility in water	reacts with water
Structure
Crystal structure	Cubic
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Strontium disilicide is a binary inorganic compound of strontium and silicon with the chemical formula SrSi₂.^[2][3]

Synthesis

Synthesis of strontium disilicide can be by fusion of strontium oxide or strontium carbonate with silicon, or silicon oxide and with coal:^[4]

SrO + 2Si + С → SrSi₂ + CO

SrCO₃ + 2SiO₂ + 4C → SrSi₂ + 4CO + CO₂

Physical properties

Strontium disilicide forms silver-gray crystals of the cubic system,^[5] space group P4₁32.^[6] The unit cell parameters are a = 6.540 Å. The density is measured at 3.40 kg/l but based on the unit cell size, it should be 3.43  kg/l. The silicon atoms form a three-dimensional lattice with the smallest Si-Si distance being 2.41 Å which is slightly more than in solid silicon. Si-Si-Si angles ∠ are 113.03°. Each silicon atom connects to three other silicon atoms. Eight silicon atoms surround each strontium atom, six at 3.21 Å and two at 3.43 Å.^[7]

Chemical properties

Water decomposes the compound:^[8]

SrSi₂ + 6H₂O → Sr(OH)₂ + 2SiO₂ + 5H₂

Also, the compound reacts with mineral acids.

Uses

SrSi₂ is reported to be a narrow-gap semiconductor or even a Weyl semimetal, with holes as the dominant charge carriers. The potential applications include thermoelectric devices and other applications where its unique properties can be utilized.^[9]

References