Synthesis, crystal structure and electrophysical properties of triple molybdates containing silver, gallium and divalent metals

Abstract

, crystal structure and electrophysical properties of triple molybdates containing silver, gallium and divalent metals A possibility of the triple molybdates formation with both NASICON-like and NaMg 3 In(MoO 4) 5 structures in the Ag 2 MoO 4-AMoO 4-Ga 2 (MoO 4) 3 (A = Mn, Co, Zn, Ni) systems was studied by powder X-ray diffraction analysis. It was established that NASICON-like phases Ag 1−x A 1−x Ga 1+x (MoO 4) 3 are not formed. The triple molybdates AgA 3 Ga (MoO 4) 5 (A = Mn, Co, Zn) isostructural to triclinic NaMg 3 In(MoO 4) 5 (sp. gr. P1, Z = 2) were synthesized and characterized. The structure of the obtained compounds was refined for AgZn 3 Ga(MoO 4) 5 according to the powder data by the Rietveld method. The structure consists of MoO 4 tetrahedra, couples of edge-shared M(1)O 6 octahedra, and trimers of edge-shared M(2)O 6-, M(3) 6and M(4)O 6 octahedra, which are linked by the common vertices to form a 3D framework. High-temperature conductivity measurements revealed that the conductivity of AgMn 3 Ga(MoO 4) 5 at 500 °С reaches 10-2 S / cm, which is close to one of the known NASICON-type ionic conductors.

Синтез и характеризация тройных молибдатов AgZn3R(MoO4)5 (R = In, Fe)

“…X-ray diffraction analysis revealed that AgZn 3 R(MoO 4 ) 5 synthesised compounds are isostructural to each other and to the previously obtained NaMg 3 R(MoO 4 ) 5 [11,12] and AgA 3 R(MoO 4 ) 5 [5][6][7][8][9][10].…”

“…One of the largest families within this class of compounds are molybdates with one-, two-, and three-charged cations. Silver NASICONlike rhombohedral phases Ag 1-x A 1-x R 1+x (MoO 4 ) 3 (A = Mg, Co, R = Al, Sc; A = Mg, R = In) [1][2][3][4] and the triclinic AgA 3 R(MoO 4 ) 5 (A = Mg, R = Cr, Fe, Ga; A = Zn, R = Ga; A = Fe II , R = Fe III ; A = Mn, R = Al, Cr, Fe, Sc, In) [5][6][7][8][9][10] are of particular interest due to a high ionic conductivity (10 -3 -10 -2 S/cm) [4,7,10]. Both structural types occur in systems where two-and three-charged cations tend to have octahedral coordination and the radius of the three-charged cation does not exceed 1 Å.…”

“…Crystals were obtained and their structure was determined for AgMg 3 R(MoO 4 ) 5 (R = Cr, Fe), AgMn [5][6][7][8]. The data from the X-ray powder patterns obtained by a full-profile analysis (Rietveld method) [13] were used to refine the crystal structures of AgM 3 Ga(MoO 4 ) 5 (M = Mg, Zn) [9,10].…”