Powder diffraction study of arsenic-substituted nasicon structures MeZr_2As_(3-x)P_xO_12(Me=Na~+,K~+)

摘要

Three new mixed oxides having the nasicon structure and containing arsenic (V) as tetrahedral ion were prepared and X-ray analyzed. The stoichiometry of the three phases can be expressed by the comprehensive notation MeZr_2As_(3-x)P_xO_12 where Me stands for Na~2 or K~+, x equals to 0 and 1.5 when Me=Na, while x equals to 1.5 when Me=K. For two other compositions of the above series, the powder patterns were calculated on the basis of the structural data form single crystal determinations, thus permitting us to complete the characterization of the solids, with nasicon framework, deriving form MeZr_2P_3O_12 (Me=Na~+, K~+) by partial (50/100) or complete (100/100) substitution of As for P.