Detection of rhombo-ortho-tetra-cubic phase transitions on poled Er3+ and Sn4+ doped BaTiO3 ceramics by up-conversion luminescence

The three ferroelectric phase transitions rhombohedral-orthorhombic-tetragonal-cubic in 0.5 mol% Er doped BaSn0.06Ti0.94O3 ceramics are detected through up-conversion luminescence measurements. Noticeable changes are observed at the phase transition temperatures in the up-converted emission line intensity at 524 nm and the integrated intensity of the green emission band (514-537 nm) under 980 nm excitation. An electrically poled surface is found to be more sensitive, and the observed phase transition temperatures by the luminescence method are in agreement with the heat capacity and dielectric phase transition temperatures. (C) 2020 Elsevier B.V. All rights reserved.