Large electrocaloric response and high energy-storage properties over a broad temperature range in lead-free NBT-ST ceramics. Issue 3 (February 2016)

• Record Type: Journal Article
• Authors: Cao, W.P.; Li, W.L.; Dai, X.F.; Zhang, T.D.; Sheng, J.; Hou, Y.F.; Fei, W.D.
• Is Part Of: Journal of the European Ceramic Society. Volume 36:Issue 3(2016)
• Page Start: 593
• Page End: 600
• Publication Date: 2016-02
• Subjects: NBT- -- BT ceramics -- Electrocaloric effect -- Energy-storage properties; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2015.10.019
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: The improvement of the electrocaloric effect (ECE) in (1− x )(Na0.5 Bi0.5 )TiO3− x SrTiO3 (NBT-ST) lead-free relaxor ferroelectric ceramics was determined by indirect measurements method and is reported here. The phase transition temperature can be reduced to room temperature by tuning the compositions of the (1− x )NBT- x ST material. A large ECE (Δ T max = 1.64 K, Δ S max = 2.52 K and Δ T /Δ E = 0.33 K mm kV −1 at 50 kV cm −1 ) was obtained at 60 °C when x = 0.25. A suitable response over a broad temperature range from 30 °C to 70 °C can be obtained with x = 0.26 with very high cooling values (Δ T > 1 K). In addition, the 0.7NBT-0.3ST AFE-like bulk ceramic exhibited excellent temperature stability in its energy-storage properties from room temperature to 120 °C. The maximum value of the recoverable energy density was 0.65 J/cm 3 obtained at 65 kV/cm. Taken together, these properties signified that (1 −x )NBT- x ST is a promising material for applications in cooling systems and energy-storage in the room temperature range.