Magnesium diboride is the inorganic compound of magnesium and boron with the formula MgB2. It is a metal boride and is particularly notable for its superconducting properties. It is a dark gray, water-insoluble solid. The compound has attracted attention because it becomes superconducting at 39 K (−234 °C). In terms of its composition, MgB2 differs strikingly from most low-temperature superconductors, which feature mainly transition metals.
Its superconducting mechanism is primarily described by BCS theory. It is notable for its superconducting properties, making it a material of interest in both basic research and practical applications, especially in the field of electronics and materials science.
Properties
- Chemical formula: MgB2
- Molar mass: 45.93 g/mol
- Density: 2.57 g/cm3
- Melting point: 830 °C (1,530 °F; 1,100 K) (decomposes)
Superconductivity
Magnesium diboride became famous in 2001 for its discovery as a relatively high-temperature superconductor, with a critical temperature (T_c) of about 39 K (−234 °C). This is significantly higher than many other conventional superconductors, which typically have much lower critical temperatures.
It exhibits superconductivity at temperatures above the boiling point of liquid hydrogen, which made it a subject of intense research after its discovery.
Applications
MgB₂’s superconducting properties make it useful in a variety of applications where high conductivity is necessary and where cooling to low temperatures is feasible. This includes:
- Magnetic resonance imaging (MRI): It can be used in the creation of strong magnetic fields for MRI machines.
- Power transmission: MgB₂ wires are being explored for use in high-efficiency power transmission.
- Magnetic levitation: It holds potential for use in maglev (magnetic levitation) trains.
Advantages over Other Superconductors
MgB₂ is simpler and cheaper to produce compared to other high-temperature superconductors, which often require complex and costly fabrication methods. It is more stable and easier to handle than other superconducting materials like yttrium barium copper oxide (YBCO), making it potentially more practical for certain applications.
