Department of Physical Chemistry, University of Science and Technology Beijing , Beijing 100083, China.
Helmholtz-Zentrum-Berlin für Materialien und Energie , Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.
J Am Chem Soc. 2018 Jan 17;140(2):602-605. doi: 10.1021/jacs.7b12235. Epub 2018 Jan 4.
Due to the advantage of invariable length with temperatures, zero thermal expansion (ZTE) materials are intriguing but very rare especially for the metals based compounds. Here, we report a ZTE in the magnetic intermetallic compounds of Tb(Co,Fe) over a wide temperature range (123-307 K). A negligible coefficient of thermal expansion (α = 0.48 × 10 K) has been found in Tb(CoFe). Tb(Co,Fe) exhibits ferrimagnetic structure, in which the moments of Tb and Co/Fe are antiparallel alignment along the c axis. The intriguing ZTE property of Tb(Co,Fe) is formed due to the balance between the negative contribution from the Tb magnetic moment induced spontaneous magnetostriction and the positive role from the normal lattice expansion. The present ZTE intermetallic compounds are also featured by the advantages of wide temperature range, high electrical conductivity, and relatively high thermal conductivity.
由于具有随温度变化的不变长度的优势，零热膨胀（ZTE）材料非常有趣，但非常罕见，特别是对于基于金属的化合物。在这里，我们报告了在宽温度范围内（123-307 K）的 Tb(Co,Fe)磁性金属间化合物中的 ZTE。在 Tb(CoFe)中发现了可忽略不计的热膨胀系数（α = 0.48 × 10 K）。Tb(Co,Fe)表现出反铁磁结构，其中 Tb 和 Co/Fe 的磁矩沿 c 轴反平行排列。Tb(Co,Fe)的这种有趣的 ZTE 性质是由于 Tb 磁矩诱导的自发磁致伸缩的负贡献与正常晶格膨胀的正作用之间的平衡所形成的。本研究中的 ZTE 金属间化合物还具有温度范围宽、电导率高和热导率相对较高的优点。
