Neutron powder diffraction of (Nd_7/12Li_1/4)TiO ₃ nano-checkerboard superlattices

Neutron powder diffraction (NPD) study of a nano-checkerboard superlattice was studied to demonstrate that the supercell model resulting from periodic phase separation is valid for crystals including transmission electron microscopy (TEM) study for the entire bulk powder sample. The phase-separated superlattice structure has 1:1 primary ordering of the A-site cations and shows the displacement of Li metal ions. Peaks in the resulting powder patterns are classified as primitive perovskite peaks present with intensity ratios and splittings to reflect the lattice parameters. A simulation of the same compound after undergoing periodic phase separation gives a periodic distribution of cations and the periodic twinning of the tilt system. The existence of R-point peaks and their splittings in the superlattice is found to be consistent with Glazer tilt system.