EELS studies of MgB 2 superconductor obtained under high pressure

Abstract

The MgB 2 intermetallic superconductor obtained under high pressure, which has the transition temperature of above 39 K, has been studied by scanning electron microscopy (SEM), transmission electron microscopy and parallel electron energy-loss spectroscopy (EELS). From the SEM, it can be seen that the bulk compound is highly dense and the grains are connected compactly. The size of single crystal is at the magnitude of ∼μm. The high resolution transmission electron microscopy image of [0 0 1] zone axis clearly shows the hexagonal planes of the constituent atoms. The EELS spectrum of B shows the peaks of σ and antibonding bonds. The EELS results show a good agreement with the theoretical band structure calculations and the hole doping in the B σ(p xy ) bonding bands.