Work

Giant electrostrain coefficient under low driving electric field in sodium potassium niobate piezoelectric ceramics with symmetrical bipolar strain

Year: 2025

Type: article

Abstract: Currently, achieving highly symmetrical bipolar strain and high electrostrain under low driving electric field remains challenging in piezoelectric materials. The designed potassium sodium niobate-based ceramics exhibit highly symmetrical bipolar strain and ultrahigh electrostrain coefficient (~2000 pm/V) under a low driving electric field of 8.4 kV/cm through A-site defect engineering and charge compensation. The highly symmetrical bipolar strain is related strongly to the lowly aligned defect dipoles by partially substituting A-site (Na+/K+) ions with Mn2+. The eye-catching performance is ascribed to the unique microstructure of atomic-scale polar nanoregions embedded in nano-domains (~34 nm) by tuning Na+/K+ ions deficiency and coexistence of multiple phases. Phase-field simulations reveal that flattened energy barrier and multiphase nanodomains interplay to boost electrostrain at low driving fields. This work provides an innovative way of designing lead-free piezoelectric materials with highly symmetrical bipolar strain and giant electrostrain coefficient at low driving electric field, promising for high-precision actuators applications. The authors design potassium sodium niobate-based ceramics exhibiting highly symmetrical bipolar strain and high electrostrain coefficient (~2000 pm/V) under a low driving electric field of 8.4 kV/cm through A-site defect engineering and charge compensation.

Source: Nature Communications

DOI: 10.1038/s41467-025-65521-5