Enhancement of piezoelectric properties of BF–BT ceramics by using ZrO2 powder bed during the sintering process

ZrO2 powders of various particle sizes (0.15, 0.7, 500 µm) were used to simulate loose powder bed sintering to prepare BF–BT piezoelectric ceramics. The phase structure, dielectric properties, ferroelectric properties, and piezoelectric properties were compared with the samples sintered by the conventional powder bed method (i.e., powder of the same composition as the sample). Results showed that the use of loose ZrO2 powder bed could improve the heat conduction rate and the sintering quality of bulk BF–BT piezoelectric ceramics. The XPS results showed that the samples sintered with 500 µm ZrO2 powder beds had the lowest concentration of Fe2+, exhibited the largest piezoelectric coefficients (d33 = 201 pC/N). In contrast, the sample sintered with a conventional powder bed under the same sintering conditions had a piezoelectric coefficient d33 of 156 pC/N.