Fig. 3

Room temperature (top) and 4.2 K (bottom) Mössbauer spectra of the Chancery MS (left) and its rim without ink (right). In all four spectra data points are shown as black dots; the black lines are the fits of the overall spectra. The individual spectral components of the part with writing (left) are given as colored lines: the pink and the olive lines are due to Fe³⁺ quadrupole doublets of which the latter one with the larger quadrupole splitting can be assigned to hydronium jarosite; the orange line is due to a Fe²⁺ quadrupole doublet assigned to Fe(II)-oxalate. In the low temperature spectrum the olive and the orange Fe doublets further split into the typical magnetic sextet of the jarosite and the octet of the Fe(II)-oxalate, respectively. The second Fe³⁺ doublet remains unchanged (pink line). Two new features of minor contribution appear, the first is a magnetic hyperfine pattern (blue line) due to a Fe³⁺ site with slow paramagnetic relaxation and the dark cyan line can assigned to a Fe²⁺ quadrupole doublet. The room temperature Mössbauer spectrum of the rim show two components: a Fe³⁺ doublet (red) and a Fe²⁺ doublet (green) with an unusually small quadrupole splitting; the corresponding 4.2 K spectrum shows again the Fe³⁺ doublet (red) and a sextet due to magnetic hyperfine splitting (blue)