  The effect of Ag addition (0-20 wt%) on polycrystalline Sr0.6K0.4Fe2As2
superconductor has been investigated. It is found that the critical transition
temperature Tc was not depressed, and the irreversibility field Hirr and
hysteresis magnetization were significantly enhanced upon Ag addition.
Characterization study reveals that larger grains are observed in the Ag-added
samples. Moreover, the formation of glassy phase as well as amorphous layer,
which are present in almost all the grain edges and boundaries in pure samples,
are suppressed by Ag addition. The improvement of superconducting properties in
Ag-added samples may originate from the enlargement of grains as well as better
connections between grains
