Synthesis, electrical and thermal properties of Bi4V2−xMexO11 (x = 0.0 and 0.02) ceramics

The bulk electrical conductivity properties of δ-Bi2O3 solid electrolyte system doped with Yb2O3

“…Also, the observed color change may be attributed to a charge transfer between oxide ions and vacancies. The existence of O 2-vacancies in the crystal lattice can also contribute to the color, because vacancy points may be occupied by electrons through a light absorption mechanism [1,17,19].…”

“…Thus, the crystal formula of pure d-form is Bi 4 O 6 , and it contains two oxygen ion vacancies on the O 2-sublattices which can be ordered or disordered (random) arrangements in the correct directions according to the some assumed crystal structure models. Moreover, this defect crystal structure plays an important role for having a high oxide ionic electrical conduction and a solid electrolyte character of d-Bi 2 O 3 [13][14][15][16][17][18][19][20][21][22][23][24][30][31][32][33][34][35]. According to the XRD results, lattice parameter variations, color changes of fcc-type solid solution, and literature data, the crystal formula of the formed d phases was supposed as seen below;…”

“…Usually these metastable phases transform to the a-phase below 500°C temperatures [9][10][11][12][13][14]. However, the d, b, and c phases of bismuth oxide can be stabilized by the addition of small amounts of other dopant M 2 O x -type oxides, such as M = Y, V, Eu, Mo, In Sm, Sb, Gd, La, Se, W, Dy, Pr, Er, Pb [2,6,10,[15][16][17]. Several authors tried that what kind of dopant materials can make the increasing effect for the oxide ion conductivity of Bi 2 O 3 -based electrolytes.…”

“…Their conductivity is mainly ionic, and oxygen ions are the mobile charge carries in the crystal structures. Generally, high temperatures and large amounts of doped M 2 O x materials introduce simultaneously oxygen vacancies which lead to increasing oxygen ionic conductivity of the bismuth oxide-type solid electrolytes [11][12][13][14][15][16][17][18][19][20][21][22][23]. According to the literature, doping of some lanthanide grouped of oxide compounds, which contain trivalent cation, can make easer stabilization of d-Bi 2 O 3 and allow forming of the phase in the larger stoichiometric range of the doping compound.…”

Synthesis, electrical and thermal properties of Bi4V2−xZrxO11 (x = 0.0, 0.02, 0.06 and 0.10) ceramics

“…The electrical conductivity of BIVOX and BIMEVOX has been reported. [15][16] The present paper reports on the synthesis, electrical and thermal properties of pure and 3% Zr-doped Bi 4 V 2 O 11 compounds.…”