High-pressure behavior of the ternary bismuth oxides image, image and image

The high-pressure behavior of Bi2Al4O9Bi2Al4O9, Bi2Mn4O10Bi2Mn4O10 and Bi2Ga4O9Bi2Ga4O9 was investigated by in situ powder synchrotron X-ray diffraction. Pressures up to 35 GPa were generated using the diamond anvil cell technique. Complementary data of the pressure dependence of Bi2Ga4O9Bi2Ga4O9 were obtained by density functional theory-based model calculations. Bi2Al4O9Bi2Al4O9 and Bi2Mn4O10Bi2Mn4O10 are structurally stable to the highest pressures obtained. In contrast, a reversible phase transition is observed in Bi2Ga4O9Bi2Ga4O9 at approximately 16 GPa. A fit of a 3rd-order Birch–Murnaghan equation of state to the p–Vp–V data results in View the MathML sourceV0=356.93(9)Å3, View the MathML sourceB0=122(2)GPa and B′=4.9(3)B′=4.9(3) for Bi2Al4O9Bi2Al4O9; View the MathML sourceV0=372.27(1)Å3, View the MathML sourceB0=138(2)GPa and B′=4.2(2)B′=4.2(2) for Bi2Mn4O10Bi2Mn4O10; and View the MathML sourceV0=388.63(3)Å3, View the MathML sourceB0=102(8)GPa and B′=3.8(2)B′=3.8(2) for Bi2Ga4O9Bi2Ga4O9. The most compressible axis is the aa axis for all the compounds. This behavior can be rationalized in terms of the inflexible polyhedra connections parallel to the bb and cc axes.