Motoaki Kaga

Crystal structure of layered perovskite compound, Li 2 LaTa 2 O 6 N

The crystal structure of Li2LaTa2O6N was determined from laboratory X-ray powder diffraction data Cu K 1 using the Rietveld method. The title compound is tetragonal with space group I4 /mmm, Z=2, and unit-cell dimensions a=0.395 049 4 nm, c=1.850 97 3 nm, and V =0.288 869 6 nm3. The initial structural model was successfully derived by the direct methods and further refined by the Rietveld method, with the anisotropic atomic displacement parameters being assigned for all atoms. The final reliability indices were Rwp=5.73%, S=1.46, Rp=4.33%, RB =1.13%, and RF=0.53%. Li2LaTa2O6N has a layered perovskite structure similar to that of Li2LaTa2O7.