The crystal structure of a new bismuth tellurium oxychloride Bi0.87Te2O4.9Cl0.87 from neutron powder diffraction data

A new bismuth tellurium oxychloride was obtained by reaction of BiOCl and TeO2 in air. According to energy dispersive X-ray spectroscopy and neutron powder diffraction refinement the composition of the substance was determined as Bi0.87Te2O4.9Cl0.87. The new compound crystallizes in the trigonal system space group R 3¯ (#148), Z=6, a=4.10793(4), c=31.1273(4) Å, χ2=3.20, wRp=0.0369. Bi0.87Te2O4.9Cl0.87 has a new type of layered structure constructed by Bi–Te–O layers separated by chloride ions. The Te atoms in Bi0.87Te2O4.9Cl0.87 show an unusual umbrella-like environment. A comparison with known related structures has been made.