Published August 1981 | Version v1
Journal article

Compounds of the type Ba3Bsup(II)M2sup(V)O9 with Bsup(II) = Mg, Ca, Sr, Ba, and Msup(V) = Nb, Ta

  • 1. Tuebingen Univ. (Germany, F.R.). Lehrstuhl fuer Anorganische Chemie 2

Description

The hexagonal perovskites Ba3Bsup(II)M2sup(V)O9 (Msup(V) = Nb, Ta) crystallize with Bsup(II) = Mg, Ca in a 3 L structure (sequence (c)3) and Bsup(II) = Sr in the hexagonal BaTiO3 type (6 L; sequence (hcc)2) with an 1:2 order for the B and M ions. Intensity calculations for Ba3SrNb2O9 and Ba3SrTa2O9 gave in the space group P63/mmc a refined, intensity related R' value of 8.4% (Nb) and 9.0% (Ta) respectively. For Bsup(II) = Ba the perovskite Ba3BaTa2O9 has an orthorhombic distorted 6 L structure and forms with Ba3SrTa2O9 a continuous series of mixed crystals (Ba3Srsub(1-x)Basub(x)Ta2O9). In the system Ba3Srsub(1-x)Basub(x)Nb2O9 the range of existence of the hexagonal BaTiO3 type is confined to the Sr richer end. The pure Ba compound posesses a proper structure type (5 L: Ba5BaNb3vacantOsub(13.5)vacantsub(1.5)). (author)

Additional details

Additional titles

Original title (German)
Ueber Verbindungen vom Typ Ba

Publishing Information

Journal Title
Z. Anorg. Allg. Chem.
Journal Volume
479
Series
Z. Anorg. Allg. Chem.
Journal Page Range
177-183
ISSN
0044-2313