Chemical Name: Magnesium boride / Magnesium diboride
Magnesium Diboride (MgB2) Description:
a) Magnesium diboride (MgB2) is an inexpensive and simple superconductor. Its superconductivity was announced in the journal Nature in March 2001. Its critical temperature (Tc) of 39 K (-234 °C; -389 °F) is the highest amongst conventional superconductors. This material was first synthesized and its structure confirmed in 1953, but its superconducting properties were not discovered until 2001. The discovery caused great excitement.
b) Though generally believed to be a conventional (phonon-mediated) superconductor, it is a rather unusual one. Its electronic structure is such that there exist two types of electrons at the Fermi level with widely differing behaviours, one of them (sigma-bonding) being much more strongly superconducting than the other (pi-bonding). This is at odds with usual theories of phonon-mediated superconductivity which assume that all electrons behave in the same manner. Theoretical understanding of the properties of MgB2 has almost been achieved with two energy gaps. In 2001 it was regarded as behaving more like a low-Tc metallic than a high-Tc cuprate superconductor.
a) Magnesium diboride has been known to scientists for approximately 50 years, however, no one had ever investigated superconductivity in the material – whether it could conduct electrical current perfectly, without resistance, when cooled to temperatures near absolute zero.
b) That all changed in January 2001 when Jun Akimitsu of Aoyama Gakuin University in Tokyo announced he and his research team had discovered that magnesium diboride becomes superconducting at 39 Kelvin (-389 F), nearly twice the temperature of current intermetallic superconductors. The announcement had experimentalists around the world rushing to duplicate and confirm the Japanese findings.
Magnesium Diboride (MgB2) Nominal Chemical Purities Available: