  The spin ice system Dy$_{2}$Ti$_{2}$O$_{7}$ exhibits strong
frequency-dependent spin-freezing at $\sim$ 16 K temperature. Although it has
been a matter of discussion for years, the origin of this unusual spin freezing
is still unknown. The replacement of Ti with isovalent Zr leads to the dynamic
magnetic ground state at low temperatures in Dy$_{2}$Zr$_{2}$O$_{7}$ and
prevents the formation of high-temperature spin freezing. Interestingly the
high-temperature spin freezing re-emerges in the presence of the magnetic
field. In this direction, we have studied a series of disordered pyrochlore
oxides A$_{2}$Zr$_{2}$O$_{7}$ (A = Eu, Gd, Er) and compared their crystal
structure, magnetic, and heat capacity behavior with that of
Dy$_{2}$Zr$_{2}$O$_{7}$ and Ho$_{2}$Zr$_{2}$O$_{7}$ systems. Our study shows
that depending on the disordered parameter, the spin-freezing behavior can be
retained by slowing down the spin dynamic with a suitable choice of the
magnetic field. We observe that unlike titanates, modification at the rare
earth site does not make considerable change in the magnetic ground state of
these zirconates compounds.
