Degradation behavior of MgB 2 superconductor

The degradation behavior of polycrystalline MgB 2 superconductor, exposed to water and ambient atmosphere, has been studied. We have found that prolonged exposure to water completely destroys superconductivity. Optical microscopic and X-ray diffraction analyses indicate that, on exposure to water, the material becomes amorphous like. X-ray photoelectron spectroscopic measurements reveal the strongly hygroscopic character of MgB 2 and we have found that, even at room temperature, water and air change it into Mg(OH) 2 , MgCO 3 and B 2 O 3 .