By using measurements at various frequencies and fields, the creep properties near to the irreversibility line were investigated. Data analysis made it possible to determine the dependence of the pinning energy, U, upon field and temperature. It was found that the dependence upon B and T could not be separated as: U(B,T) = U0(B)f(T). Self-consistent experiments proved that differing creep mechanisms were active in the low-frequency/low-field and high-frequency/high-field regions.

Creep Properties of MgB2 Bulk Near the Irreversibility Line. G.Ghigo, D.Botta, A.Chiodoni, R.Gerbaldo, L.Gozzelino, E.Mezzetti, B.Minetti, S.Ceresara, G.Giunchi, G.Ripamonti: Superconductor Science and Technology, 2001, 14, 722-5