Silver manganese alloys of composition Ag100-xMnx (25 <= x <= 40) were prepared by rapid solidification to investigate their reported antiferromagnetic character. Thorough characterization of their structural, compositional, and magnetic features indicates the formation of a phase-separated fcc-type structure in all studied alloys with lattice parameters and coherently diffracting region sizes on the order of 40-100 nm that are strongly correlated with the Mn content. Magnetic measurement reveals a blocking temperature T-B similar to 105 K that is accompanied by unprecedented exchange bias values up to 1.7 T (17 kOe) at low temperatures. The magnitudes of the exchange bias field and the blocking temperature increase with increasing Mn concentration, suggesting a very sensitive balance between Mn content and magnetic character in these alloys that fosters tuning of the resultant exchange bias. (C) 2012 American Institute of Physics. [doi:10.1063/1.3679048]