Hysteretic phenomena in the quaternary solid-solution system 0,98(хРЬТЮз-I/PbZrOa-zPbNb2/3Mgi/<sub>3</sub>0<sub>3</sub>)-0,02PbGeO<sub>3</sub>
<i>The phase diagrams of two sections of the solid solutions system 0,98(xPbTi0</i><sub><i>3</i></sub><i>-yPbZr0</i><sub><i>3</i></sub><i></i>- <i>zPbNb2/</i><sub><i>3</i></sub><i>Mg</i><sub><i>1/3</i></sub><i>0</i><sub><i>3</i></sub><i>)</i>-<i>0,02PbGeO</i><sub><i>3</i></sub><i> were constructed from the results of X-ray studies. The longitudinal strains Ј</i><sub><i>3</i></sub><i> and converse piezoelectric coefficients d</i><sub><i>33</i></sub><i> of the solid solutions were measured. Correlations between the positions of extremes of the studied characteristics and the phase boundaries were established. Recommendations on using of the data obtained in designing the materiab with the prescribed values of parameters were given.</i>