Zhao Wenjun, Sun Ying, Liu Yufei, Shi Kewen, Lu Huiqing, Song Ping, Wang Lei, Han Huimin, Yuan Xiuliang, Wang Cong
Department of Physics, Center for Condensed Matter and Materials Physics, Beihang University, Beijing, China.
Capital Normal University High School, Beijing, China.
Front Chem. 2018 Feb 6;6:15. doi: 10.3389/fchem.2018.00015. eCollection 2018.
Fe-doped MnNiGe alloys were successfully synthesized by solid-state reaction. Giant negative thermal expansion (NTE) behaviors with the coefficients of thermal expansion (CTE) of -285.23 × 10 K (192-305 K) and -1167.09 × 10 K (246-305 K) have been obtained in MnFeNiGe and MnNiFeGe, respectively. Furthermore, these materials were combined with Cu in order to control the NTE properties. The results indicate that the absolute value of CTE gradually decreases with increasing Cu contents. In MnFeNiGe/%Cu, the CTE gradually changes from -64.92 × 10 K (125-274 K) to -4.73 × 10 K (173-229 K) with increasing value of from 15 to 70. The magnetic measurements reveal that the NTE behaviors in this work are strongly correlated with the process of the magnetic phase transition and the introduction of Fe atoms could also change the spiral anti-ferromagnetic (s-AFM) state into ferromagnetic (FM) state at low temperature. Our study launches a new candidate for controlling thermal expansion properties of metal matrix materials which could have potential application in variable temperature environment.
通过固态反应成功合成了铁掺杂的锰镍锗合金。在MnFeNiGe和MnNiFeGe中分别获得了热膨胀系数（CTE）为-285.23×10⁻⁶ K⁻¹（192 - 305 K）和-1167.09×10⁻⁶ K⁻¹（246 - 305 K）的巨大负热膨胀（NTE）行为。此外，将这些材料与铜结合以控制NTE性能。结果表明，CTE的绝对值随着铜含量的增加而逐渐降低。在MnFeNiGe/%Cu中，随着铜含量从15增加到70，CTE逐渐从-64.92×10⁻⁶ K⁻¹（125 - 274 K）变化到-4.73×10⁻⁶ K⁻¹（173 - 229 K）。磁性测量表明，这项工作中的NTE行为与磁相变过程密切相关，并且引入铁原子还可以在低温下将螺旋反铁磁（s-AFM）状态转变为铁磁（FM）状态。我们的研究为控制金属基材料的热膨胀性能推出了一种新的候选材料，这种材料在可变温度环境中可能具有潜在应用。
