Structure and electrical properties of lanthanum-doped CaBi4Ti4O15–Bi4Ti3O12 intergrowth ferroelectric

• High Curie temperature.
• Bismuth layer-structure ferroelectric.
• Piezoelectric ceramic.

Structure and electrical properties of lanthanum-doped CaBi4Ti4O15–Bi4Ti3O12 (CaBi(8−x)LaxTi7O27, CBT–BIT–xLa) intergrowth ferroelectric were studied. With increasing the La3+ content, CBT–BIT–xLa showed increased lattice parameters and decreased grain sizes. The total La3+ content in BIT part is similar to that in CBT part. The dielectric loss was decreased with La3+ doping. Both remnant polarization (2Pr) and the coercive electric field (Ec) increase with increasing La3+ content at 0.0≤x≤0.4, show maximum values of 24.5 μC/cm2 and 60.8 kV/cm with x=0.4, and decrease when x≥0.4. Meanwhile, the piezoelectric constant (d33) increases as the doping level of La3+ increases from 0.0 to 0.8, gets a maximum value of 23.4 pC/N at x=0.8, and then decreases.

Figure optionsDownload as PowerPoint slide