  The solid solution $0.5Ba(Ti_{0.8}Zr_{0.2})O_3$-$0.5(Ba_{0.7}Ca_{0.3})TiO_3$
(BCZT) has become a promising member of the lead-free piezoelectric materials
because of its exceptionally high piezoelectric properties. In this study, we
focus on studying pressure-dependent Raman spectroscopy, powder x-ray
diffraction and dielectric constant measurements on BCZT. The data show several
structural transitions are present, where the system from ambient mixed phase
(tetragonal, {\it {P4mm}}+ orthorhombic {\it {Amm2}}) transforms into single
phase ({\it {P4mm}}) at 0.26 GPa, then converts into cubic phase ({\it {Pm3m}})
at 4.7 GPa followed by another possible structural re-ordering around 10 GPa.
Although there have been a lot of unanimity with the ambient crystallographic
state of BCZT, our analysis justifies the presence of an intermediate
orthorhombic phase in the Morphological Phase Boundary (MPB) of BCZT phase
diagram. The transformation tetragonal to cubic is indicated by the Raman mode
softening, unit cell volume change and the $(Ti/Zr)O_6$ octahedra distortion,
which coincides with the well-known ferroelectric-paraelectric transition of
the system. The sudden drop in the dielectric constant value at 4.7 GPa also
confirms the loss of ferroelectric nature of the BCZT ceramic.
