Achieving negative thermal expansion over an extended temperature range in rare‐earth‐modified PbTiO 3 ‐based perovskites

作者：Zhao Pan, Meng-Qi Ye, Yan Suo, Fengyi Zhou, Duo Wang, Jin Liu, Xu-Bin Ye, Jie Zhang, Maocai Pi, Weihao Li, Chao Chen, Ning Lü, Shogo Kawaguchi, Yao Shen, Youwen Long · 发表于：Rare Metals · 年份：2025 · DOI：10.1007/s12598-025-03310-1 · 被引用次数：4 · 研究领域：Thermal Expansion and Ionic Conductivity、Ferroelectric and Piezoelectric Materials、Microwave Dielectric Ceramics Synthesis

Abstract Negative thermal expansion (NTE) is a notable physical property where a material’s volume decreases instead of increasing when heated. The identification of NTE materials is crucial for thermal expansion control engineering. Most NTE materials exhibit NTE only within a narrow temperature range, restricting their applications. Achieving NTE across a broad temperature range remains a significant challenge. This study developed a novel PbTiO 3 ‐based system, (1‐ x )PbTiO 3 – x BiLuO 3 , incorporating rare‐earth elements, using a distinctive high‐pressure and high‐temperature synthesis technique. We achieved NTE across a broad temperature range by coupling lattice ( c / a ) with ferroelectric order parameters. The incorporation of BiLuO 3 resulted in distinctive ferroelectric characteristics, including increased tetragonality, spontaneous polarization, and NTE over a broad temperature range. NTE over an extended temperature range has been achieved in 0.95PbTiO 3 –0.05BiLuO 3 ( = −1.7 × 10 –5 K −1 , 300–840 K) and 0.90PbTiO 3 –0.10BiLuO 3 ( = −1.4 × 10 –5 K −1 , 300–860 K), compared to pristine PbTiO 3 ( = −1.99 × 10 –5 K −1 , 300–763 K). The improved tetragonalities and broader NTE temperature range result from the strong hybridization of Pb/Bi–O and Ti/Lu–O atoms, as demonstrated by combined experimental and theoretical analyses, including high‐energy synchrotron X‐ray diffraction, Raman spectroscopy, and density functional theory calculations. This study introduces a n...