Ion Doping Effects on the Lattice Distortion and Interlayer Mismatch of Aurivillius-Type Bismuth Titanate Compounds.

Taking Bismuth Titanate (Bi₄Ti₃O) as a Aurivillius-type compound with = 3 for example, the ion (W/Cr) doping effect on the lattice distortion and interlayer mismatch of Bi₄Ti₃O structure were investigated by stress analysis, based on an elastic model. Since oxygen-octahedron rotates in the ab-plane, and inclines away from the c-axis, a lattice model for describing the status change of oxygen-octahedron was built according to the substituting mechanism of W/Cr for Ti, which was used to investigate the variation of orthorhombic distortion degree () of Bi₄Ti₃O with the doping content. The analysis shows that the incorporation of W/Cr into Bi₄Ti₃O tends to relieve the distortion of pseudo-perovskite layer, which also helps it to become more stiff.

Indentation Behavior and Mechanical Properties of Tungsten/Chromium co-Doped Bismuth Titanate Ceramics Sintered at Different Temperatures.

A sort of tungsten/chromium(W/Cr) co-doped bismuth titanate (BIT) ceramics (Bi₄TiWO + 0.2 wt % Cr₂O₃, abbreviate to BTWC) are ordinarily sintered between 1050 and 1150 °C, and the indentation behavior and mechanical properties of ceramics sintered at different temperatures have been investigated by both nanoindentation and microindentation technology. Firstly, more or less Bi₂Ti₂O₇ grains as the second phase were found in BTWC ceramics, and the grain size of ceramics increased with increase of sintering temperatures.