Samples of Y1-xCaxSr2GaCu2O7-delta (x = 0, 0.4) doped with Fe-57, prep
ared under various oxygen pressures, have been studied by magnetometry
and Mossbauer spectroscopy. Most of the iron ions (Fe3+) enter the Ga
(Cu(1)) site. For the x = 0 sample, the Mossbauer spectra of the iron
nuclei in the Cu(2) sublattice display magnetic order of Cu, T-N = 370
K. The iron ions in the Ga site display magnetic order only at low te
mperatures. At temperatures above 90 K, these iron ions display a pure
quadrupole doublet Mossbauer spectrum. The sample x = 0.4 also displa
ys magnetic order of the Cu(2) site, T-N approximate to 370 K. A sharp
drop in the hyperfine field is observed at T-N, probably associated w
ith a first-order phase transition or two-dimensional ordering. The ir
on nuclei in the Ga site display paramagnetic long spin relaxation tim
e phenomena at 4.2 K. The x = 0.4 sample prepared under 110 atm oxygen
pressure, displays superconductivity, T-c approximate to 50 K. The Mo
ssbauer spectra give evidence of the presence of two phases. One displ
ays magnetic order, the other is paramagnetic, the last is probably as
sociated with the superconducting phase.