  This work reports on the systematic high pressure Raman studies in the
PbZr$_{1-x}$Ti$_x$O$_3$ ($0.02 \leq x \leq 0.14$) ceramics performed at room
temperature. The pressure dependence of the Raman spectra reveals the stable
phases of the material under pressure variation. The results allowed us to
propose a concentration-pressure phase diagram for rich Zr PZT system up to
pressures of 5.0 GPa.
