Phase structure analysis and pyroelectric energy harvesting performance of Ba(HfxTi1-x)O3 ceramics

Ba(Ti1-xHfx)O-3 ceramics were synthesized by a solid-state reaction process. The evolution of the phase structure was identified by XRD spectrum, dielectric spectroscopy, and temperature-dependent Raman spectroscopy for the Ba(Ti1-xHfx)O-3 ceramics. In addition, pyroelectric energy harvesting properties based on the Olsen cycle were investigated for the first time. A maximum pyroelectric energy harvesting density value of N-D=491.30 kJ/m(3) (T=120 degrees C, E-H=50 kV/cm) was achieved in the Ba(Hf0.05Ti0.95)O-3 ceramic. Compared with those of BT, the values of N-D more than doubled in the temperature range from T=60 degrees C to T=100 degrees C in the Ba(Hf0.05Ti0.95)O-3 ceramic and even increased 3.2 times at T=80 degrees C near the Curie temperature (T-C) of the Ba(Hf0.05Ti0.95)O-3 sample. In addition, a larger pyroelectric energy harvesting density value of N-D=367.10 kJ/m(3) (T=120 degrees C, E-H=50 kV/cm) was acquired in the Ba(Hf0.12Ti0.88)O-3 ceramic. Values of ND-BHT5/ND-BT and ND-BHT12/ND-BT were analyzed in the Ba(Ti1-xHfx)O-3 ceramics. The optimal pyroelectric properties can be obtained in the vicinity of the ferroelectric to paraelectric phase-transition region.