Preparation, crystal structure, and luminescence of zeolite Ta,Cl,Cs,Na-A containing a cubic Cs11TaCl 6 10+ continuum

Abstract

The anhydrous zeolite |(Cs11TaCl6) 0.11 10+ Cs 4.4 + Na 4.5 + |[Si14Al10O48]-A was prepared to study its expected X-ray luminescence. Fully dehydrated Cs7Na5-A was treated with TaCl5(g, 4.8 × 104 Pa) at 483 K for 48 h under anhydrous conditions. The structure of the product was determined by single-crystal X-ray diffraction using synchrotron X-radiation in the space group Pm $$\bar 3$$ m (a = 12.219(1) A). It was refined using all data to the final error index (for the 799 unique reflections for which F o > 4σ(F o)) R 1 = 0.074. Its composition was confirmed by energy dispersive X-ray analysis. Octahedral TaCl6 − ions center about 11% of the large cavities. Each coordinates to eight Cs+ ions and they are further bridged by Cs+ ions in the planes of 8-rings to form a cubic three-dimensional Cs11TaCl 6 10+ continuum in the near surface volume of the crystal. The X-ray luminescence spectrum of this material is a broad band between 350 and 650 nm, peaking primarily at 380 nm. Toward applications in radiation detection, this lies within the best working range of a commercial photomultiplier tube.