Giant Negative Thermal Expansion in NaZn13-Type La(Fe, Si, Co)13 Compounds
Giant Negative Thermal Expansion in NaZn13-Type La(Fe, Si, Co)13 Compounds
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DOI：
10.1021/ja405161z
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发表时间：
2013-08-07
影响因子：
15
通讯作者：
Li, Laifeng
中科院分区：
文献类型：
--
作者：
Huang, Rongjin;Liu, Yanying;Li, Laifeng
基于La（Fe，Si）（13）的化合物是众所周知的磁热材料，其在居里温度附近显示出显著的负热膨胀（NTE），但尚未被认为是用于工业应用的NTE材料。合成了NaZn_（13）型LaFe_（13-x）Six和LaFe_（11.5-x）CoxSi_（1.5）化合物，研究了它们的线性NTE特性。通过优化化学成分，成功地将La（Fe，Si）（13）基化合物的急剧体积变化改变为连续膨胀。通过增加LaFe11.5-xCoxSi1.5中Co掺杂剂的量，NTE向更高的温度区域移动，并且NTE操作温度窗口也变得更宽。典型地，在LaFe10.5Co1.0Si1.5化合物中确定的线性NTE系数达到多达-26.1 x 10（-6）K-1，具有从240至350 K的110 K的操作温度窗口，其包括室温。这种对La（Fe，Si）（13）基化合物的特定组成和NTE性质的控制暗示了它们作为NTE材料的潜在应用。
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 x 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.