Enhancement of electro-strain performance of KTaO3 modified 0.94Bi0.5Na0.5TiO3-0.06BaTiO3 ceramics

Abstract

The (1−[Formula: see text])(0.94Bi[Formula: see text]Na[Formula: see text]TiO3–0.06BaTiO 3)–[Formula: see text]KTaO3(BNBT–[Formula: see text]KT) lead-free ferroelectric ceramics were produced using the traditional solid-state sintering technique, and the phase structure, surface morphology, electrical properties were all thoroughly examined. Every ceramic has a single perovskite structure and there is no second phase, as shown by the XRD patterns and Raman spectra. Scanning electron microscopy revealed that all samples displayed dense microstructure and cubic grain. In addition, KT encourages grain growth due to the oxygen vacancies induced by doping or volatilization of ions at high temperatures. The [Formula: see text][Formula: see text]of the ceramics decreases with increasing doping levels due to oxygen vacancies acting as dipoles upon the addition of KT, and the dielectric loss of all samples is low at ambient temperature. In comparison to the pure BNBT ceramic’s bipolar strain value of 0.12%, the BNBT–2KT ceramic achieved a maximum bipolar strain of [Formula: see text]0.506% and unipolar strain of [Formula: see text] 0.430% with the corresponding [Formula: see text][Formula: see text]*up to 538 pm/V under 80 kV/cm field. Performance significantly improved as a result of this. A test of the correlation between temperature and ferroelectric properties shows that the largest strain value of the BNBT–2KT ceramic occurs at ambient temperature and that the phase change from ferroelectric to relaxor is complete. Additionally, it is discovered that the BNBT–3KT ceramic can sustain a stable strain across a broad temperature range, suggesting that it has good temperature stability. The aforementioned findings demonstrate that lead-based ceramics may be replaced with BNBT–[Formula: see text]KT ceramics.