Spectroscopic study of the low‐dimensional (C 3 H 7 NH 3 ) 2 CdCl 4 crystal irradiated with X‐rays

The optical absorption spectra of the two‐dimensional crystals of n ‐(C 3 H 7 NH 3 ) 2 CdCl 4 induced by X‐ray irradiation at 20 K were studied and compared with those for the as‐received sample. It has been found that X‐irradiation causes effects similar to those observed in the related crystals of (C n H 2 n +1 NH 3 ) 2 CdCl 4 ( n = 1, 2). New optical absorption bands (IR bands) were found in the region 10–17 kcm –1 , besides the absorption band of the Cl 2 – molecular center characteristic of this compound. The absorption intensities of these bands decrease at temperatures higher than 40 K accompanying the decrease of the Cl 2 – concentration in n‐ (C 3 H 7 NH 3 ) 2 CdCl 4 crystals. These IR bands are assigned to the electron‐trapped center where an electron is trapped by an alkylammonium head in the neighborhood of a Cl – vacancy. Such a model was found to be in good agreement with the results of the X‐ray luminescence and thermoluminescence study. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)