Strontium hexaboride

Strontium boride
Names
Other names
strontium hexaboride
Identifiers
12046-54-7 Yes
EC number 234-969-8
Jmol-3D images Image
PubChem 6336904
Properties
SrB6
Molar mass 152.49 g/mol
Appearance black crystalline powder
Density 3.39 g/cm3, solid (15.0°C)
Melting point 2,235 °C (4,055 °F; 2,508 K)
insoluble
Structure
Crystal structure Cubic
Space group Pm3m ; Oh
Hazards
EU classification not listed
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
0
1
0
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Strontium boride (SrB6) is an inorganic compound. At room temperature, it appears as a crystalline black powder.[1] Closer examination reveals slightly translucent dark red crystals capable of scratching quartz.[2] It is very stable and has a high melting point and density. Although not thought to be toxic, it is an irritant to the skin, eyes, and respiratory tract.[1]

Magnetism

Strontium boride, along with other alkali-earth metal borides, has been shown to exhibit weak ferromagnetism at low temperatures.[3] This is thought by some to be caused by slight impurities or aberrations in the crystal lattice,[4][5] while others suggest different explanations are needed.[6] Strontium boride has also been examined for semiconducting properties at lower temperatures.[7]

Preparation

In his book The Electric Furnace, Henri Moissan describes an early synthesis of strontium boride by mixing strontium borate, aluminum, and carbon in an electric furnace.[2] Alternatively, a solid-phase synthesis of strontium boride can be carried out by reacting two moles of strontium carbonate with three moles of boron carbide and one mole of carbon inside a vacuum furnace.[8]

Uses

Strontium boride is used in insulation and nuclear control rods.[8] A recent patent filed for aircraft windows uses SrB6 nanoparticles in a transparent acrylic sheet. The IR-absorbing properties of these nanoparticles prevents the transmittance of infrared wavelengths while still allowing the transmittance of visible light.[9]

References

  1. ↑ 1.0 1.1 http://www.espimetals.com/msds%27s/strontiumboride.pdf
  2. ↑ 2.0 2.1 Moissan, Henri. The Electric Furnace.
  3. ↑ D. P. Young, D. Hall, M. E. Torelli, Z. Fisk, J. L. Sarrao, J. D. Thompson, H. R. Ott, S. B. Oseroff, R. G. Goodrich, and R. Zysler. High-temperature weak ferromagnetism in a low-density free-electron gas. Nature (London), 397, 412 (1999).
  4. ↑ Shang, S., & Liu, Z. "Thermodynamics of the B–Ca, B–Sr, and B–Ba systems: Applications for the fabrications of CaB6, SrB6, and BaB6 thin films". Applied Physics Letters, 2007, 90, 091914-1. Retrieved April 30, 2009, doi:10.1063/1.2710081
  5. ↑ J. L. Gavilano, B. Ambrosini, H. R. Ott, D. P. Young, Z. Fisk, "Low-temperature NMR studies of SrB6", Physica B: Condensed Matter, Volumes 281–282, 1 June 2000, Pages 428–429, ISSN 0921-4526, doi:10.1016/S0921-4526(99)01197-7 (http://www.sciencedirect.com/science/article/B6TVH-400WKV6-68/2/9b3bc29604aac16dd96856e9c7aab187)
  6. ↑ Dorneles, L., Venkatesan, M., Moliner, M., Lunney, J., & Coey, J. "Magnetism in thin films of CaB6 and SrB6". Applied Physics Letters, 2004, 85, 6377–6379. Retrieved April 30, 2009, doi:10.1063/1.1840113
  7. ↑ H. R. Ott, M. Chernikov, E. Felder, L. Degiorgi, E. G. Moshopoulou, J. L. Sarrao, Z. Fisk. Structure and low temperature properties of SrB6. Z. Phys. B, 1997, 102, 337–345.
  8. ↑ 8.0 8.1 Shu-Qi Zheng, Zeng-Da Zou, Guang-Hui Min, Hua-Shun Yu, Jian-De Han, Wei-Ti Wang. "Synthesis of strontium hexaboride powder by the reaction of strontium carbonate with boron carbide and carbon". Journal of Materials Science Letters, 2002, 21, 313–315.
  9. ↑ "United States Patent Application 20090093578". Retrieved 2009-05-05.