Giant Negative Thermal Expansion in NaZn13-Type La(Fe, Si, Co)13 Compounds

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• 作者：Rongjin Huang ; Yanying Liu ; Wei Fan ; Jie Tan ; Furen Xiao ; Lihe Qian ; Laifeng Li
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：August 7, 2013
• 年：2013
• 卷：135
• 期：31
• 页码：11469-11472
• 全文大小：280K
• 年卷期：v.135,no.31(August 7, 2013)
• ISSN：1520-5126

文摘

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 LaFe_13鈥?i>xSi_x and LaFe_11.5鈥?i>xCo_xSi_1.5 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 LaFe_11.5鈥?i>xCo_xSi_1.5, 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 LaFe_10.5Co_1.0Si_1.5 compound reaches as much as 鈭?6.1 脳 10^鈥? K^鈥?, 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.