  We have carried out the powder x-ray diffraction and dielectric studies on
multiferroic particulate composite xNi0.9Zn0.1Fe2O4/(1-x)PbZr0.52Ti0.48O3 with
x=0.15, 0.30, 0.45, 0.60, 0.75 and 0.90 to explore the structural and
ferroelectric properties. A conventional double sintering method was used to
prepare the xNi0.9Zn0.1Fe2O4/(1-x)PbZr0.52Ti0.48O3 composites. The structure of
one of the component Ni0.9Zn0.1Fe2O4 is spinel cubic with space group Fd3m,
while the other component PbZr0.52Ti0.48O3 is selected around the morphotropic
phase boundary region in which the tetragonal and monoclinic phases with space
group P4mm and Cm coexist respectively. We have carried out Rietveld refinement
of the structure to check the formation of ideal composites with separate
ferroelectric and ferrite phases. Even though the structural characterization
does not reveal the formation of any new phase due to reaction between the two
components of the composite during sintering, the tetragonality of the
PbZr0.52Ti0.48O3 continuously decreases with increasing the ferrite fraction
while the lattice parameter of ferrite phase increases with increasing fraction
of the ferroelectric phase. Similarly, the dielectric study reveals clear shift
in the ferroelectric to paraelectric phase transition temperature of
PbZr0.52Ti0.48O3 during composite formation suggesting that part of Ni2+, Zn2+/
Fe3+ ions are diffusing at the B-site of PbZr0.52Ti0.48O3 replacing Ti4+, which
in turn decreases its transition temperature. Scanning electron micrograph of
sintered pellet surface confirms the presence of two types of particle
morphology in the particulate composite, corresponding to ferrite and
ferroelectric phases.
