  We present abundances of Mn, Cu, Zn and various light and heavy elements for
a sample of barium and normal giant stars, and present correlations between
abundances contributed to different degrees by the weak-s, main-s, and
r-processes of neutron capture, between Fe-peak elements and heavy elements.
Data from the literature are also considered in order to better study the
abundance pattern of peculiar stars. The stellar spectra were observed with
FEROS/ESO, and the stellar atmospheric parameters of the 8 barium giant stars
and 6 normal giants analyzed by us lie in the range 4300 < T_eff/K < 5300, -0.7
< [Fe/H] <= 0.12 and 1.5 <= log g < 2.9. Carbon and nitrogen abundances were
derived by the spectral synthesis of molecular bands of C_2, CH and CN. For all
the other elements, atomic lines were used to perform the spectral synthesis. A
very large scatter was found when data from the literature were considered,
mainly for the Mn abundances. We found that [Zn/Fe] correlates well with the
heavy element excesses, its abundance clearly increasing as the heavy element
excesses increase, a trend not shown by the [Cu/Fe] and [Mn/Fe] ratios. Also,
the excess of Mn, Cu and Zn relative to heavy elements usually show an
increasing trend toward higher metallicities. Our results suggest that a larger
fraction of the synthesis of Zn is owed to massive stars than is the case of
Cu, and that the contribution of the main-s process to the synthesis of both
elements is small. We also conclude that Mn is mostly synthesized by SN Ia, and
that a non-negligible fraction of the synthesis of Mn, Cu and Zn is owed to the
weak s-process.
