Metal precipitation in one-dimensional crystal of CsMnCl3 center dot 2H(2)O

Visible metal precipitation of a golden luster has been observed in CsMnCl3 . 2H(2)O which was irradiated with X- or gamma-rays at room temperature. It does not occur when it is irradiated at 77 K and then warmed to room temperature. A continuous optical absorption was observed ranging from 2 eV to higher energy more than 5.50 eV (225 nm), An absorption band overlaps at 3.55 eV (350 nm), which is nearly the same as those of the V-k center (Cl-2(-)) in KCl and RbCl. It suggests that the 3.55 eV band originates from the self-trapped hole centers (Cl-2(-)) in the present crystal.