Aging behavior and electrical properties of low-temperature sintered (Ba, Ca)(Ti, Zr)O 3 -Ba(Cu, W)O 3 ceramics and plate loudspeaker
Abstract Lead-free (1 −  x )wt.% (Ba 0.85 Ca 0.15 )(Zr 0.10 Ti 0.90 )O 3  −  x  wt.% (Ba(Cu 0.5 W 0.5 )O 3 (BCZT −  x  wt.% BCW) piezoelectric ceramics were prepared by solid-state reaction. The phase structure of the ceramics showed that the orthorhombic–tetragonal phase boundary was identified in the range of 1.2 ≤  x  ≤ 1.6 wt.%. The dense microstructure and optimal electrical properties of the ceramics were obtained at x  = 1.2 wt.%. Fatigue behavior of the ceramics was also investigated as a function of temperature and keeping time, where the BCZT − 1.2 wt.% BCW materials were found to possess improved fatigue characteristic. In addition, the sound pressure level (SPL) of 16.0 mm length × 16.0 mm width × 0.1 mm piezoelectric loudspeakers using lead-free BCZT ceramics with 1.2 wt.% BCW content at drive voltage of 10–20 V was more than 80 dB at frequency of 2.2–20.0 kHz. These results indicated that the 98.8 wt.% BCZT − 1.2 wt.% BCW ceramics was potential for piezoelectric loudspeaker applications.