Santucci Simone, Vasiljevic Milica, Zhang Haiwu, Tinti Victor Buratto, Bergne Achilles, Morin-Martinez Armando A, Chaluvadi Sandeep Kumar, Orgiani Pasquale, Sanna Simone, Lyksborg-Andersen Anton, Hansen Thomas Willum, Castelli Ivano E, Pryds Nini, Esposito Vincenzo
Department of Energy Conversion and Storage, Technical University of Denmark, Lyngby, Denmark.
Atlant 3D, Taastrup, Denmark.
Nat Commun. 2025 Jan 2;16(1):36. doi: 10.1038/s41467-024-55393-6.
Electrostriction is the upsurge of strain under an electric field in any dielectric material. Oxygen-defective metal oxides, such as acceptor-doped ceria, exhibit high electrostriction 10 mV values, which can be further enhanced via interface engineering at the nanoscale. This effect in ceria is "non-classical" as it arises from an intricate relation between defect-induced polarisation and local elastic distortion in the lattice. Here, we investigate the impact of mismatch strain when epitaxial Gd-doped CeO thin films are grown on various single-crystal substrates. We demonstrate that varying the compressive and tensile strain can fine-tune the electromechanical response. The electrostriction coefficients achieve a large M ≈ 3.6·10 mV in lattices of in-plane compressed films, i.e., a positive tetragonality (c/a-1 > 0), with stress above 3 GPa at the film/substrate interface. Chemical and structural analysis suggests that the high electrostriction stems from anisotropic distortions in the local lattice strain, which lead to constructively oriented elastic dipoles and Ce electronic defects.
电致伸缩是指任何介电材料在电场作用下应变的激增。缺氧金属氧化物，如受主掺杂的二氧化铈，表现出高电致伸缩值（10 mV），通过纳米尺度的界面工程可进一步提高该值。二氧化铈中的这种效应是“非经典的”，因为它源于缺陷诱导极化与晶格中局部弹性畸变之间的复杂关系。在此，我们研究了在各种单晶衬底上生长外延钆掺杂二氧化铈薄膜时失配应变的影响。我们证明，改变压缩应变和拉伸应变可以微调机电响应。在面内压缩薄膜的晶格中，即正四方性（c/a - 1 > 0），当薄膜/衬底界面处的应力高于3 GPa时，电致伸缩系数达到较大的M ≈ 3.6·10 mV。化学和结构分析表明，高电致伸缩源于局部晶格应变中的各向异性畸变，这导致了建设性取向的弹性偶极子和铈电子缺陷。
