An X-Ray Powder and Electron Diffraction Study of Reduced Tantalates with the Perovskite Structure, Na1−xSrxTaO3, 0<x≤0.4

Synthesis, Crystal Structure, and Spectrum Properties of a New Quaternary Borate NaSr7AlB18O36 with the Cyclic B18O36 18− Group, Notation of 6 × (3[2Δ + 1T])

“…and Na ? cations have similar oxygen coordination geometries and a similar situation has also been previously observed in the structures of Sr 0.3 Na 0.7 NbO 3 [13], Sr 0.3 Na 0.7 TaO 3 [14], and Sr 3.67 Na 0.33 PtO 6 [15]. The NaSr 7 AlB 18 O 36 crystal has also been checked on a Rigaku AFC7R four-circle diffractometer with a slower scan rate and lower intensity limitation, no symmetry lower than rhombohedral or a larger unit cell that would allow Sr 2?…”

Structures and Properties of the Perovskite-Type Compounds Na1−xSrxNbO3 (0.1≤x≤0.9)—From Insulating to Metallic Conductivity

“…For several years we have been interested in these types of transitions in reduced d 0 2d 1 oxoniobates and oxotantalates. Recently, we reported the synthesis of the first reduced oxotantalates with perovskite-type structure Na 1Àx Sr x TaO 3 ð0:0rxr0:4Þ (5,6). In this system, the resistivity decreases with increasing strontium content but metallic conductivity was not reached even for the highest strontium content Na 0.6 Sr 0.4 TaO 3 .…”