Ionic conductivity of potassium antimonate tungstates with partial Na+ or Li+ substitution for K+

Structure and ionic conductivity of solid solutions in the K2CO3-AgNO3-Sb2O3-MeO3 System (Me = W or Mo)

“…In [2][3][4], the established concentration boundaries of the formation of potassium antimonate tungstate phases with a pyrochlore type structure allowed one to dope this system with sodium, lithium [3], and silver ions and form substitutional solid solutions with a wide homogeneity region.…”

“…Alternating current investigations according to the technique [5] of the ionic conductivity of potassium antimonate tungstate of the KSbWO 6 and Me 0.4 K 0.6 SbWO 6 compositions (Me = Na, Li, or Ag) showed [3] that it exponentially grows with an increase in the sample temperature in the range of 500-1000 K (Fig. 6).…”

“…4, point 5). It was noted pre viously that the pyrochlore structure framework can be stabilized by introducing potassium ions into the cat ionic sublattice (8b sites) [3]. The stabilizers in these phases are silver ions.…”

“…It was noted previously [3] that ion transport in the obtained phases can be implemented via a system of channels, which are formed by 16d and 8b sites in the 〈111〉 lattice directions. The ionic conductivity of the samples decreases with an increase in the potassium ion content in the K y -x Me x Sb y W 2 -y O 6 and K y ⎯ x Me x Sb y Mo 2 -y O 6 phases (Me = Na, Li, or Ag), while the activation energy increases.…”

“…Taking into account the similar ionic radii of Sb(V) and W(VI)/Mo(VI), one would expect the formation of potassium antimonate tungstate and antimonate molybdate solid solutions doped with silver ions with a wide homogeneity region, which are iso morphic to pyrochlore and have ionic conductivity [3].…”