Gradient-Acceptor-Doping Breaks the Piezoelectric Trade-Off in Lead-Free (K, Na)NbO<sub>3</sub> Ceramics.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41388582.
- Also identified by DOI 10.1002/adma.202521306.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Achieving a high piezoelectric coefficient (d<sub>33</sub>) and a high mechanical quality factor (Q<sub>m</sub>) simultaneously in ferroelectric ceramics has been a persistent challenge, as conventional doping strategies, i.e., donor doping and acceptor doping, inevitably sacrifice one for the other. Here, the inherent trade-off is breaking through a new gradient-acceptor-doping strategy. By judiciously introducing gradient Cu<sup>2+</sup>-acceptor ions in "soft" (K, Na)NbO<sub>3</sub> (KNN) ceramics, a record combination of properties is achieved - a d<sub>33</sub> of 350 pC/N and a Q<sub>m</sub> of 340,-the first co-elevation of both parameters exceeding 300 in KNN-based systems. This represents a fourfold improvement in Q<sub>m</sub> with only a 10% reduction in d<sub>33</sub>. Multi-scale structural analysis reveals that the gradient doping retains a "soft" interior for high d<sub>33</sub>, and creates a "hardened" surface layer that effectively restrains domain switching, accounting for the enhanced Q<sub>m</sub>. This work offers a new paradigm for designing high-power ferroelectric ceramics by spatially tailoring functional properties.