High temperature channeling analysis of YBa2Cu3O7-δ single crystals

A novel RBS system for channeling analysis at high temperatures has been constructed. Utilizing this RBS system equipped with 950 keV He+ ions, we have conducted channeling analysis on the (001) and (100) surfaces of YBa2Cu3O7-δ single crystals, at temperatures ranging from 20 C to 780 C. Our experiments revealed that the surfaces deteriorated from around 400 C in oxygen pressures below 5 x 10-5 Torr, as the sample temperature was increased. The surface deterioration at high temperatures was found to be strongly dependent on the oxygen pressure. The deterioration was significant in oxygen pressures below 10-4 Torr or at pressures above 10 Torr. In oxygen pressures between 10-3 and 1 Torr, however, the surfaces were stable at high temperatures and no surface deterioration was observed. (orig.)