DEFECT FORMATION IN LAYERED IONIC-CRYSTALS OF (CNH2N-CENTER-DOT-2H2O(1NH3)(2)MCL(4) (M=CD, CU, MN, N=1, 2, 3) AND CSMNCL3)

Metal precipitation has been observed in the two dimensional crystals of alkylammonium metal chlorides. (CnH2n+1NH3)(2)MCl(4) which were X- or gamma-irradiated at 77 K and warmed to room temperature. It has bee n also observed in tile one dimensional crystals of CsMnCl3.2H(2)O whi ch was irradiated at room temperature similar as photochromism of silv er halides. The different temperature conditions of metal precipitatio n suggest a variety of defect formation mechansims. In alkylammonium m etal chlorides, Cl-2(-) molecule ions are formed at 77 K and electron trap centers are observed at 15 K with X-ray irradiation. The electron trap centers are very unstable and are bleached at temperatures highe r than 30 K.