Tuning the electrocaloric enhancement near the morphotropic phase boundary in lead-free ceramics.
The need for more energy-efficient and environmentally-friendly alternatives in the refrigeration industry to meet global emission targets has driven efforts towards materials with a potential for solid state cooling. Adiabatic depolarisation cooling, based on the electrocaloric effect (ECE), is a significant contender for efficient new solid state refrigeration techniques. Some of the highest ECE performances reported are found in compounds close to the morphotropic phase boundary (MPB). This relationship between performance and the MPB makes the ability to tune the position of the MPB an important challenge in electrocaloric research. Here, we report direct ECE measurements performed on MPB tuned NBT-06BT bulk ceramics with a combination of A-site substitutions. We successfully shift the MPB of these lead-free ceramics closer to room temperature, as required for solid state refrigeration, without loss of the criticality of the system and the associated ECE enhancement.
Department of Materials, Imperial College London, London, SW7 2AZ, UK.
Florian
F
Le Goupil
School of Engineering and Materials Science, Queen Mary University of London, 380 Mile End Road, London E1 4NS, UK.
Ruth
R
McKinnon
Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 040 01 Kosice, Slovak Republic.
Vladimir
V
Koval
School of Engineering and Materials Science, Queen Mary University of London, 380 Mile End Road, London E1 4NS, UK.
Giuseppe
G
Viola
School of Engineering and Materials Science, Queen Mary University of London, 380 Mile End Road, London E1 4NS, UK.
Steve
S
Dunn
Department of Materials, Imperial College London, London, SW7 2AZ, UK.
Andrey
A
Berenov
School of Engineering and Materials Science, Queen Mary University of London, 380 Mile End Road, London E1 4NS, UK.
Haixue
H
Yan
Department of Materials, Imperial College London, London, SW7 2AZ, UK.
Neil McN
NM
Alford