A Review of Bismuth-Rich Binary Oxides in the Systems Bi2O3–Nb2O5, Bi2O3–Ta2O5, Bi2O3–MoO3, and Bi2O3–WO3

Stability and range of the type II Bi 1−x W x O 1.5+1.5x solid solution

“…Arguably the most interesting amongst these are the cubic 'type II' (3+3)-dimensional incommensurately modulated solid solution phases [4][5][6][7][8][9][10]. These phases are characterized by a series of three coupled modulations of the fluoritetype subcell <ε 0 0>f.…”

The exchange interactions and the state of manganese atoms in the solid solutions in Bi3NbO7 of cubic and tetragonal modifications

“…The tetragonal phase is formed in the temperature range from 800 to 900°C and is stable on cooling to room temperature. Beyond this temperature range (4750°С) bismuth niobate crystallizes in cubic syngony [14,15]. The phase transition from tetragonal structure to cubic structure was found earlier to be reversible [16].…”

“…In the binary Вi 2 O 3 -Nb 2 O 5 system upon the mole ratio of bismuth to niobium 1.0r n(Bi)/n(Nb) r 5.3 the formation of four types of crystal structures derivative from fluorite structure were found [13,14]. Bismuth niobate Bi 3 NbO 7 has two polymorphic modifications -tetragonal (type III) and cubic (type II) [14].…”

“…Bismuth niobate Bi 3 NbO 7 has two polymorphic modifications -tetragonal (type III) and cubic (type II) [14]. The tetragonal phase is formed in the temperature range from 800 to 900°C and is stable on cooling to room temperature.…”

“…Niobium atoms are located in distorted octahedra of oxygen atoms [9,14]. As a result of examining the crystal structure of bismuth niobate and its solid solutions by the methods of neutron and electron diffraction niobium atoms were found to be distributed in the lattice in a non-statistic manner [9,10,[14][15][16][17][18][19][20][21]. Niobium-oxygen octahedra are combined in chains and blocks via oxygen atoms.…”