Local structure investigation of the ferroelectric phase transition of BaSn0.1Ti0.9O3 using neutron pair distribution function

Local structural distortions in BaTiO3-solid solutions, where Ti site is substituted by isovalent Sn cation Ba(Sn,Ti)O3, are characterized not by oxygen tilts but the existence of different Ti(Sn)-O bonds, leading to different polar orders, from ferroelectrics to relaxors. For the ferroelectric BaSn0.1Ti0.9O3 compound, we carried out synchrotron radiation diffraction experiments to investigate the structural sequence through the ferroelectric transition happening at 300K, but extending through 20K, from the low temperature ferroelectric R3m phase to the high temperature paraelectric Pm-3m one. Our experiments using synchrotron pair distribution function did not allow us to determine any local structure change through the ferroelectric transition. Neutron scattering pair distribution function will allow us quantifying local disorder and symmetry, identifying the role played by Sn and Ti.