Hydrothermal synthesis,crystal structure,thermal behaviour,IR and Raman spectroscopy of Na_3Y(CO_3)_3 centre dot 6 H_2O

摘要

A new sodium yttrium carbonate hydrate,Na_3Y(CO_3)_3 centre dot 6 H_2O,is prepared by hydrothermal synthesis and characterized by single crystal X-ray diffraction,thermal analysis,IR and Raman spectroscopy.Na_3Y(CO_3)_3 centre dot 6 H_2O crystallizes in the hexagonal system,space group P6_3 ;a=11.347(5)A,c=5.935(5)A;V= 661.8(5)A~3;Z=2.Refinements yield R(F~2)= 0.058 and R_w(F~2)= 0.161 for 692 unique reflections.The structure is built up from [YO+(3+3+3)] polyhedra surrounded by [NaO_6] octahedra.Carbonate groups form infinite layers at z=0.175 and z=0.675.Dehydration of Na_3Y(CO_3)_3 centre dot 6 H_2O yields an amorphous carbonate.