Crystallite size effect on lattice strain and crystal structure of Ba1/4Sr3/4MnO3 layered perovskite manganite.

The single phase polycrystalline Ba_1/4Sr_3/4MnO₃ layered perovskite manganite has been synthesized by combustion method having various crystallite sizes. The room temperature X-ray diffraction patterns reveal that Ba_1/4Sr_3/4MnO₃ crystallizes into hexagonal crystal structure with space group P6₃/mmc as confirmed by Rietveld refinement. The scanning electron micrographs of Ba_1/4Sr_3/4MnO₃ 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. [ABSTRACT FROM AUTHOR]