X-ray photo-emission measurements were made of Mg 2p and B 1s core levels from MgB2 as well as of the O 1s core level from O contaminant. The motivation for this study came from a discrepancy in reported work on the energy values of the B 1s and Mg 2p core levels; ostensibly due to impurity-O reacting to form oxides and other compounds. Sputtering led to a significant reduction of O on, and in, the sample. The in situ sputter-cleaned sample gave the best results.

Core Level Photoemission Study of Polycrystalline MgB2. K.B.Garg, T.Chatterji, S.Dalela, M.Heinonnen, J.Leiro, B.Dalela, R.K.Singhal: Solid State Communications, 2004, 131[5], 343-7