層状ペロブスカイトNa2La2Ti3O10の構造解析とイオン伝導性

An ion-exchangeable layered perovskite compound, Na2La2Ti3O10, was directly synthesized by a solid-state reaction. The crystal structure of Na2La2Ti3O10 was determined by electron diffraction analysis and Rietveld analysis for the powder X-ray diffraction pattern. The unit cell is tetragonal with a=0.383528 (7) nm, c=2.85737 (7) nm and Z=2 with the space group I4/mmm (No. 139). The structure of this compound is analogous to that of the Ruddlesden-Popper phases. The ionic conductivity of Na2La2Ti3O10 was not very high compared with those of niobate compounds, NaLaNb2O7 and NaCa2NaNb4O13. Such a low ionic conductivity is due to the rigid rock-salt-type coordination around sodium ions located at the interlayer