  We have studied vortex pinning and dynamics in a Sr0.6K0.4Fe2As2
superconducting tape with critical current density Jc~0.1 MA/cm2 at 4.2 K and
10 T. It is found that grain boundary pinning is dominant in the vortex pinning
mechanism. Furthermore, we observe large density of dislocations which can also
serve as effective pinning centers. We find that the temperature dependence of
critical current density is in agreement with the model of vortices pinned via
spatial fluctuation of charge carrier mean free path. Magnetic relaxation
measurement indicates that the magnetization depends on time in a logarithmic
way. The relaxation rate in the low and intermediate temperature region is
small, and it exhibits a weak temperature and field dependence. A crossover
from elastic creep to plastic creep regime is observed. Finally, we conclude a
vortex phase diagram for the high performance Sr0.6K0.4Fe2As2 superconducting
tape.
