  The single phase polycrystalline Ba1/4Sr3/4MnO3 layered perovskite manganite
has been synthesized by combustion method having various crystallite sizes. The
room temperature X-ray diffraction patterns reveal that Ba1/4Sr3/4MnO3
crystallizes into hexagonal crystal structure with space group P63/mmc as
confirmed by Rietveld refinement. The scanning electron micrographs of
Ba1/4Sr3/4MnO3 reveal uniform crystallite size of the samples. Effect of
crystallite size on lattice strain and crystal structure has been studied using
Rietveld refinement and Williamson-Hall plot, respectively. The structural
lattice parameters decrease with increasing crystallite size. However, lattice
strain increases with increasing crystallite-size.
