Giant piezoelectricity of Sm-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals

• Published in: Science (American Association for the Advancement of Science) 2019-04, Vol.364 (6437), p.264-268
• Main Authors: Li, Fei, Cabral, Matthew J, Xu, Bin, Cheng Zhenxiang, Dickey, Elizabeth C, LeBeau, James M, Wang, Jianli, Luo, Jun, Taylor, Samuel, Hackenberger Wesley, Bellaiche Laurent, Xu, Zhuo, Long-Qing, Chen, Shrout, Thomas R, Zhang, Shujun
• Format: Article
• Language: English
• Subjects: Charge materials; Crystal growth; Crystals; Ferroelectric crystals; Ferroelectric materials; Ferroelectricity; First principles; Heterogeneity; Lead; Lead titanates; Mathematical analysis; Piezoelectricity; Properties (attributes); Rare earth elements; Relaxors; Samarium; Scanning electron microscopy; Scanning transmission electron microscopy; Single crystals; Transducers; Transmission electron microscopy
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aaw2781

Samarium supersensorsPiezoelectric materials produce electric charge in response to changes in stress and are thus good sensor materials. One challenge has been growing single-crystal piezoelectrics with uniform properties. As of now, much of the crystal is discarded because of compositional variations. Li et al. synthesized single crystals of samarium-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 that have uniform and extremely high piezoelectric properties (see the Perspective by Hlinka). These crystals are ideal for a variety of sensing applications and could reduce cost by eliminating waste.Science, this issue p. 264; see also p. 228High-performance piezoelectrics benefit transducers and sensors in a variety of electromechanical applications. The materials with the highest piezoelectric charge coefficients (d33) are relaxor-PbTiO3 crystals, which were discovered two decades ago. We successfully grew Sm-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 (Sm-PMN-PT) single crystals with even higher d33 values ranging from 3400 to 4100 picocoulombs per newton, with variation below 20% over the as-grown crystal boule, exhibiting good property uniformity. We characterized the Sm-PMN-PT on the atomic scale with scanning transmission electron microscopy and made first-principles calculations to determine that the giant piezoelectric properties arise from the enhanced local structural heterogeneity introduced by Sm3+ dopants. Rare-earth doping is thus identified as a general strategy for introducing local structural heterogeneity in order to enhance the piezoelectricity of relaxor ferroelectric crystals.