Large field-induced strain with enhanced temperature-stable dielectric properties of AgNbO3-modified (Bi0.5Na0.5)0.94Ba0.06TiO3 lead-free ceramics

(1-x)(Bi0.5Na0.5)(0.94)Ba0.06TiO3-xAgNbO3 lead-free piezoelectric ceramics (abbreviated as BNBT-100xAN) were prepared using the conventional solid-state sintering method. The effects of the introduction of AgNbO3 (AN) dopants for the dielectric and piezoelectric performances of BNBT-100xAN ceramics were systematically studied. The XRD patterns and Raman spectra demonstrated that AN as a modifier was successfully diffused into the BNBT-100xAN lattice and revealed a pseudo-cubic symmetry structure. All samples exhibited a dense surface morphology accompanied by the uniform distribution of elements. A large bipolar strain of similar to 0.501% and unipolar strain of similar to 0.481% corresponding to the normalized strain d(33)* of similar to 740 p.m./V were achieved for BNBT-1AN ceramic at 65 kV/cm field. The BNBT-4AN ceramic exhibited an excellent temperature-stable permittivity with the range from 59 to 380 degrees C and its dielectric loss was less than 0.02 between 97 degrees C and 329 degrees C. These results revealed that BNBT-100xAN ceramics were more hopeful candidates for actuators, strain sensors, and high-temperature capacitors.

Automated summary

The introduction of AgNbO3 dopants into BNBT-100xAN ceramics significantly improved their dielectric and piezoelectric properties, allowing them to perform well under high voltage and temperature conditions. XRD patterns and Raman spectra showed successful diffusion of AN modifiers into the lattice with a pseudo-cubic symmetry structure. These results demonstrate the potential of BNBT-100xAN ceramics for strain sensors and high-temperature capacitors.