Abstract:
We report on the dielectric properties of bismuth aluminate and gallate with Bi:Al(Ga) ratio of 1:1 and 12:1 prepared at high temperature
and ambient pressure. These compounds crystallize in a noncentrosymmetric body-centered cubic structure (space group I23) with a ∼10.18 Å rather than in the perovskite structure. This cubic phase is related to the γ -Bi2O3 structure which has the actual chemical formula
Bi3+24 (Bi3+ Bi5+)O40− δ. In the aluminates and gallates studied by us, the Al and Ga ions are distributed over the 24 f and 2a sites. These
compounds exhibit ferroelectric hysteresis at room temperature with a weak polarization.
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