A comprehensive structural analysis of relaxor ferroelectric Cr- and Ni-doped Sr0.61Ba0.39Nb2O6 crystals

A structural features, real compositions, and point defects of nominally pure and Cr- and Ni-doped Sr 0.61 Ba 0.39 Nb 2 O 6 (SBN) crystals, which structure contains four chemically-different and ten crystallochemically-different atoms, have been determined using neutron, X-ray single crystal, X-ray powder, and X-ray synchrotron diffraction techniques, and EXAFS/XANES spectroscopy. The location of transition metal ions has been identified based on the analysis of electron (nuclear) density and confirmed by the EXAFS/XANES together with the definition of formal charges of Ni atoms in Ni-doped SBN crystals. The scope and application possibilities of diffraction methods and EXAFS/XANES spectroscopy for the determination of structural features and defect formation in functional bulk nominally-pure and Cr- and Ni-doped Sr 0.61 Ba 0.39 Nb 2 O 6 single crystals is established.