Enhanced electrical performance in CaBi4Ti4O15 ceramics through synergistic chemical doping and texture engineering

High-temperature piezoelectric materials with excellent piezoelectricity, low dielectric loss and large resistivity are highly desired for many industrial sectors such as aerospace, aircraft and nuclear power. Here a synergistic design strategy combining microstructural texture and chemical doping is employed to optimize CaBi4Ti4O15 (CBT) ceramics with bismuth layer structure. High textured microstructure with an orientation factor of 80%–82 % has been successfully achieved by the spark plasma sintering technique. Furthermore, by doping MnO2, both advantages of hard doping and sintering aids are used to obtain the excellent electrical performance of d33 = 27.3 pC/N, tanδ∼0.1 %, Q31∼2307 and electrical resistivity ρ∼6.5 × 1010 Ω cm. Up to 600 °C, the 0.2 % (in mass) Mn doped CBT ceramics still exhibit high performance of d33 = 26.4 pC/N, ρ∼1.5 × 106 Ω cm and tanδ∼15.8 %, keeping at an applicable level, thus the upper-temperature limit for practical application of the CBT ceramics is greatly increased. This work paves a new way for developing and fabricating excellent high-temperature piezoelectric materials.