The sensible superconductor

Until the magnesium diboride revelation, engineers trying to apply superconductivity to the real world had to grapple with distinctly un-ideal materials. Low-temperature (metallic) superconductors, while not too costly and with excellent mechanical properties, require cooling down nearly to zero-4.2K-a pricey proposition. High-temperature (ceramic) superconductors can be cooled at far less expnse to a less chilly 77K, but their manufacturing process requires a great deal of silver, a costly material. With a superconducting transition temperature of 39K, it can be convieniently cooled with commerical cryocoolers or liquid hydrogen.