Doping-induced diffused phase transition triggers gas-sensing performance of Sn-doped BaTiO3 nanostructures

The formation of polar nanoregions with a smaller doping concentration of Sn into BaTiO3 nanostructures governs significantly better gas-sensing response for a NO2 gas at room temperature. Appropriate Sn doping in BaTiO3 nanostructures not only modifies the electronic structure but is also responsible for diffused phase transition in its crystal structure. Here, in this study, we performed high-resolution transmission electron microscopy of the Sn-doped BaTiO3 samples to observe the formed polar nanoregions; 0.2 M% Sn-doped BaTiO3 possesses a higher polarization value at room temperature to adsorb NO2 gas on the surface of the thick film resistor-based gas sensor, improving its gas-sensing performance. The electronic structure and density of states of pristine and Sn-doped BaTiO3 were studied by density functional theory calculations, and the results of the same revealed improved gas-sensing performance in the case of Sn-doped BaTiO3 nanostructures.