Effect of shock-wave loading on bismuth oxide-containing piezo- and ferroelectrics

The effect of shock-wave loading on bismuth and germanium oxides, their mechanical mixtures, and the compounds Bi$_{12}$GeO$_{20}$, Bi$_4$Ge$_3$O$_{12}$, and Bi$_2$GeO$_5$ in the form of single- and polycrystals was studied by methods of physicochemical analysis. It was established that the distribution of the elements Bi, Ge, and Fe is nonuniform because of displacement of layers from the surface into the bulk. In bismuth and germanium oxides after loading, the effect of admixtures (iron oxide and oxygen) and distortion of the crystal lattices were revealed. Under shock-wave loading, the starting components in a mixture with composition of 6:1 react to form the metastable Bi$_2$GeO$_5$ phase. A comparison of differential thermal analysis data of specimens on heating and cooling with metastable state diagrams makes it possible to distinguish between the effects of stuctural distortions and of admixtures on the properties of the materials after loading.