  In this paper, we reported the effect of Cu doping on the structural and
dielectric properties of Ba$_2$Y$_{1-x}$Cu$_x$TaO$_{6-y}$ (0.00 $\leq$ x $\leq$
0.50) ceramics at room temperature. The Copper for Yttrium substitution reduces
the sintering temperature and leads to structural changes in the Ba$_2$YTaO$_6$
rock-salt crystalline structure. Dielectric permittivity and complex impedance
spectroscopy measurements suggested enhancement of the dielectric constant and
occurrence of interfacial Maxwell-Wagner polarization.
