Abstract
The coexistence of positive and negative electrocaloric effects (ECE) was observed in the sol-gel derived Pb-free perovskite structured (Bi1/2Na1/2)1-xBaxTiO3 (x = 0, 0.04, 0.05, 0.06, 0.07) (BNBT) ceramics. The maximum electrocaloric temperature change of 2.35 °C has been observed at 100 kV/cm for x = 0.06 at about 70 °C before the ferroelectric to antiferroelectric (FE-to-AFE) phase transition temperature. The coexistence of positive and negative ECE at different temperatures may be attributed to two different temperature dependent phase transitions in the ferroelectrics or antiferroelectrics. The sign reversal of ECE in the same material can be utilized to increase the efficiency of the refrigeration cycle and to develop efficient environmentally friendly cooling systems.
Original language | English |
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Article number | 105929 |
Journal | Solid State Sciences |
Volume | 95 |
DOIs | |
Publication status | Published - 1 Sept 2019 |
Keywords
- Electrocaloric effect
- Ferroelectric ceramics
- Lead-free
- Solid state refrigerants
ASJC Scopus subject areas
- General Chemistry
- General Materials Science
- Condensed Matter Physics