Synergistically optimizing electrocaloric effects and temperature span in KNN-based ceramics utilizing a relaxor multiphase boundary.
In: Journal of Materials Chemistry C, Jg. 8 (2020-03-28), Heft 12, S. 4030-4039
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Zugriff:
A combination of large adiabatic temperature change (ΔT) and wide temperature span (T span ) in lead-free ceramics is highly desired to develop eco-friendly and highly efficient solid-state refrigeration based on electrocaloric effects. However, the lack of success in synergistically optimizing both large ΔT and wide T span in one material impedes the practical applications of electrocaloric refrigeration technology. Here, a relaxor multiphase boundary (RMPB) is structured in (1 − x)(K 0.49 Na 0.49 Li 0.02 )(Nb 0.8 Ta 0.2 )O 3 –xCaZrO 3 (KNLNT–xCZ) ceramics through intentional composition engineering, successfully achieving a region of multiphase coexistence accompanied by diffuse phase transition. A moderate ΔT (0.63 K under 80 kV cm −1 ) with a wide T span (43 K within 90% ΔT attenuation) is obtained in a relaxor KNLNT–5CZ ceramic with the coexistence of an R–O–T phase. The results indicate that a coupling effect originally from multi-directional polarization and polar nano-regions (PNRs) in RMPB contributes to the excellent performance combining large ΔT and wide T span . This work not only expands the applications of KNN-based ceramics from electric energy storage and piezoelectric applications to the refrigeration field, but also opens up a new design avenue for the development of high performance electrocaloric materials with broad temperature ranges. [ABSTRACT FROM AUTHOR]
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Titel: |
Synergistically optimizing electrocaloric effects and temperature span in KNN-based ceramics utilizing a relaxor multiphase boundary.
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Autor/in / Beteiligte Person: | Yang, Junlin ; Zhao, Ye ; Lou, Xiaojie ; Wu, Jiagang ; Hao, Xihong |
Zeitschrift: | Journal of Materials Chemistry C, Jg. 8 (2020-03-28), Heft 12, S. 4030-4039 |
Veröffentlichung: | 2020 |
Medientyp: | academicJournal |
ISSN: | 2050-7526 (print) |
DOI: | 10.1039/c9tc06443e |
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