Giant Negative Thermal Expansion in NaZn 13 -Type La(Fe, Si, Co) 13 Compounds

作者：Rongjin Huang, Yanying Liu, Wei Fan, Jie Tan, Furen Xiao, Lihe Qian, Laifeng Li · 发表于：Journal of the American Chemical Society · 年份：2013 · DOI：10.1021/ja405161z · 被引用次数：295 · 研究领域：Thermal Expansion and Ionic Conductivity、Magnetic and transport properties of perovskites and related materials、Ferroelectric and Piezoelectric Materials

La(Fe, Si)13-based compounds are well-known magnetocaloric materials, which show a pronounced negative thermal expansion (NTE) around the Curie temperature but have not been considered as NTE materials for industrial applications. The NaZn13-type LaFe13-xSix and LaFe11.5-xCoxSi1.5 compounds were synthesized, and their linear NTE properties were investigated. By optimizing the chemical composition, the sharp volume change in La(Fe, Si)13-based compounds was successfully modified into continuous expansion. By increasing the amount of Co dopant in LaFe11.5-xCoxSi1.5, the NTE shifts toward a higher temperature region, and also the NTE operation-temperature window becomes broader. Typically, the linear NTE coefficient identified in the LaFe10.5Co1.0Si1.5 compound reaches as much as -26.1 × 10(-6) K(-1), with an operation-temperature window of 110 K from 240 to 350 K, which includes room temperature. Such control of the specific composition and the NTE properties of La(Fe, Si)13-based compounds suggests their potential application as NTE materials.