Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (07): 1823-1831.doi: 10.3866/PKU.WHXB20100726

• STRUCTURE CHEMISTRY • Previous Articles     Next Articles

Syntheses, Structures and Properties of Hemi-Hydrogarnet Sr6Sb4M3O14(OH)10 (M=Co,Mn)

LI Kuo, WANG Ying-Xia, SU Jie, LIN Jian-Hua   

  1. Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
  • Received:2010-03-25 Revised:2010-04-19 Published:2010-07-02
  • Contact: WANG Ying-Xia, LIN Jian-Hua E-mail:wangyx@pku.edu.cn; jhlin@pku.edu.cn

Abstract:

Two new compounds, Sr6Sb4Co3O14(OH)10 (SSC) and Sr6Sb4Mn3O14(OH)10 (SSM), were synthesized under hydrothermal conditions in an alkaline medium. Their structures were determined by powder X-ray diffraction using Rietveld analysis, and the topology of the metal cation network was discussed. These two isostructural compounds crystallize in a garnet-related or hydrogarnet-related structure with the space group I43d and the lattice parameters (a) are 1.30634(2) nm(SSC) and 1.31367(1) nm(SSM). The SbO6 octahedron and MO4 (M=Co, Mn) tetrahedron share corners with each other to formthe backbone of the structure. The topology of the Sb5+ andM2+ (M=Co,Mn) network is ctn, which is the C3N4network. The Sb5+ node is three-connected and that of M2+ (M=Co, Mn) is four-connected. The distribution of the M2+ (M=Co, Mn) cations in the structure is in a fanlike mode with a thp topology, i.e., a network of Th atoms in Th3P4. These two compounds are antiferromagnetic. Sr6Sb4Co3O14(OH)10 exhibits a net magnetic moment, which may be related to the canting ordering of Co2+ ions below 10 K. Sr6Sb4Co3O14(OH)10 and Sr6Sb4Mn3O14(OH)10 decompose above 300 ℃ and give rise to the perovskite-type compounds Sr2(Sb, M)2O6(M=Co, Mn) as the main phases in the products after treatment at 900 ℃ under atmospheric conditions.

Key words: Topological structure, Hemi-hydrogarnet, Hydroxyl oxide, Rietveld structure refinement, Antiferromagnetic

MSC2000: 

  • O641