Magnetic relaxation behavior, critical current density JC and lower critical field HC1 were investigated in MgB2/Ta/Cu wires. It was found that JC and HC1 decrease linearly with temperature in the whole temperature region below TC. The relaxation rate was very small and had a weak temperature dependence compared to high-TC superconductors. Also, the pinning potential was much larger and the temperature and field dependences of the pinning potential were briefly considered.

Magnetic Relaxation and Lower Critical Field in MgB2 Wires. Y.Feng, G.Yan, Y.Zhao, A.K.Pradhan, C.F.Liu, P.X.Zhang, L.Zhou: Journal of Physics - Condensed Matter, 2003, 15, 6395-402