AI 中文总结
研究利用CBED与4D-STEM对Pb(Mg1/3Nb2/3)O3中PNRs和CORs进行实空间映射及温度依赖性研究，发现CORs抑制PNR生长，PNRs有渗流转变，支持随机场模型，为理解弛豫铁电体性能提供重要成像证据。
AI 中文摘要
极性纳米区域（PNRs）对于理解弛豫铁电体优异的介电和压电性能至关重要，也是推进高储能电介质的关键。然而，对其形成和演化进行直接实空间成像仍是凝聚态物理的一大挑战。本文利用会聚束电子衍射（CBED）结合四维扫描透射电子显微镜（4D-STEM），报道了典型弛豫体Pb(Mg1/3Nb2/3)O3中PNRs和化学有序区域（CORs）的实空间映射及其温度依赖性。结果表明，尺寸为2-5nm的CORs随温度保持静态，抑制PNR生长。相比之下，PNRs从室温下孤立的2-5nm区域演变为低温下约10nm大小的互连结构，表明发生了渗流转变。这些观察结果支持随机场模型，其中PNRs从顺电基质中出现，其生长和集体相互作用受与CORs相关的随机局部场约束。
英文摘要
Polar nanoregions (PNRs) are central to understanding the exceptional dielectric and piezoelectric properties of relaxor ferroelectrics and are key to advancing dielectrics for high-energy storage. However, direct real-space imaging of their formation and evolution remains a major challenge in condensed matter physics. Here, we report the real-space mappings of both PNRs and chemically ordered regions (CORs) in the prototypical relaxor Pb(Mg1/3Nb2/3)O3 and their temperature dependence using convergent-beam electron diffraction (CBED) combined with four-dimensional scanning transmission electron microscopy (4D-STEM). The results reveal that CORs, with sizes of 2-5 nm, remain static with temperature and act to suppress PNR growth. In contrast, PNRs evolve from isolated 2-5 nm regions at room temperature to interconnected structures ~10 nm in size at low temperatures, indicative of a percolation transition. These observations support the random-field model, in which PNRs emerge from a paraelectric matrix and their growth and collective interactions are constrained by random local fields associated with CORs.
Comments12 pages, 4 figures
Journal refAppl. Phys. Lett. 128, 142901 (2026)
