The origin of low bandgap and ferroelectricity of a co-doped BaTiO3D. Phuyal, S. Mukherjee, S. Das, S. Jana, K. O. Kvashnina, D. D. Sarma, H. Rensmo, S. M. Buortin and O. KarisEPL, 124 2 (2018) 27005DOI: https://doi.org/10.1209/0295-5075/124/27005