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]
^Shang, S.; Liu, Z. (2007). "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. 90 (9): 091914. Bibcode:2007ApPhL..90i1914S. doi:10.1063/1.2710081.
