Figure 6.
(a) electron paramagnetic resonance (EPR) spectra of pristine Bi4Ti3O12 and Bi4Ti3O12−x after chemical reduction treatment (a) at 350 °C for different times; (b) at different temperatures for 60 min; and (c) thermogravimetric analysis (TGA) curves of the pristine Bi4Ti3O12, Bi4Ti3O12−x (350 °C, 40 min), and Bi4Ti3O12−x (350 °C, 60 min).