fig4
From: Investigation of BiFeO3-BaTiO3 lead-free piezoelectric ceramics with nonstoichiometric bismuth

Figure 4. Temperature-dependent εr and tanδ of (A) -0.01 ≤ x ≤ 0.04 measured at 10 kHz, (B) the Tm at 10 kHz, (C) the relaxation coefficient γ at 10 kHz, (D) the ΔTm from 1 kHz to 1 MHz for the B1+xF-BT ceramics.