抄録
We synthesized the perovskite-type oxides with A-site vacancies, Sr0.5NbO3, Sr0.5TaO3 and Sr0.5Nb0.5Ta0.5O3, via nanosheet process using (SrNb2O7)2- nanosheets and/or (Sr1.5Ta3O10)2- nanosheets. Raman scattering demonstrates that nanosheet-processed Sr0.5Nb0.5Ta0.5O3 have a novel structure composed of the alternate stacking of the several layers of Sr0.5NbO3 and Sr0.5TaO3 along the c axis. Dielectric measurements (1 MHz) of pressed powder exhibited that nanosheet-processed Sr0.5TaO3 showed a much higher permittivity of 52 compared with solid-state-reacted Sr0.5TaO3 (33). Nanosheet-processed Sr0.5Nb0.5Ta0.5O3 with B-site-cation ordering had a lower permittivity of 42 than that with B-site-cation disordering (65). These results suggest that the stacking faults induced by nanosheet process and the arrangement of B-site cations play an important role in dielectric permittivity.
