The influence, upon the peak effect, of increasing the density of uncorrelated defects was studied in a de-twinned single crystal. The defects were introduced by 9MeV proton irradiation to total doses ranging from 2.5 x 1014 to 2 x 1015/cm2. After each irradiation, the peak effect shifted downwards and was eventually suppressed by a sufficiently high irradiation dose. The peak effect reappeared after high-temperature annealing; thus suggesting that it was mainly the point-defect population which was introduced by irradiation that interfered with the manifestation of the peak effect.

Effects of Successive Proton Irradiations on the Peak Effect in Cu3Ba2YO7 Single Crystals. V.Tobos, L.M.Paulius, A.M.Petrean, S.Ferguson, J.W.Snyder, R.J.Olsson, W.K.Kwok, G.W.Crabtree: Applied Physics Letters, 2001, 78[20], 3097-9