Hu Jinyu, Lin Kun, Cao Yili, Yu Chengyi, Li Wenjie, Huang Rongjin, Fischer Henry E, Kato Kenichi, Song Yuzhu, Chen Jun, Zhang Hongjie, Xing Xianran
Beijing Advanced Innovation Center for Materials Genome Engineering, Department of Physical Chemistry, and State Key Laboratory of Advanced Metals and Materials , University of Science and Technology Beijing , Beijing 100083 , China.
Key Laboratory of Cryogenics , Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190 , China.
Inorg Chem. 2019 May 6;58(9):5401-5405. doi: 10.1021/acs.inorgchem.9b00480. Epub 2019 Apr 24.
Metallic materials that exhibit negligible thermal expansion or zero thermal expansion (ZTE) have great merit for practical applications, but these materials are rare and their thermal expansions are difficult to control. Here, we successfully tailored the thermal expansion behaviors from strongly but abruptly negative to zero over wide temperature ranges in a series of (Gd,R)(Co,Fe) (R = Dy, Ho, Er) intermetallic compounds by tuning the composition to bring the first-order magnetic phase transition to second-order. Interestingly, an unusual isotropic ZTE property with a coefficient of thermal expansion of α = 0.16(0) × 10 K was achieved in cubic GdDyCoFe (GDCF) in the temperature range of 10-275 K. The short-wavelength neutron powder diffraction, synchrotron X-ray diffraction, and magnetic measurement studies evidence that this ZTE behavior was ascribed to the rare-earth-moment-dominated spontaneous volume magnetostriction, which can be controlled by an adjustable magnetic phase transition. The present work extends the scope of the ZTE family and provides an effective approach to exploring ZTE materials, such as by adjusting the magnetism or ferroelectricity-related phase transition in the family of functional materials.
具有可忽略不计的热膨胀或零热膨胀（ZTE）的金属材料在实际应用中具有很大优势，但这类材料稀少且其热膨胀难以控制。在此，我们通过调整成分使一系列（Gd，R）（Co，Fe）（R = Dy、Ho、Er）金属间化合物在宽温度范围内成功地将热膨胀行为从强烈但突然的负膨胀调整为零膨胀，即将一阶磁相变转变为二阶磁相变。有趣的是，在立方GdDyCoFe（GDCF）中，在10 - 275 K温度范围内实现了一种异常的各向同性ZTE特性，其热膨胀系数α = 0.16(0)×10⁻⁶ K⁻¹。短波长中子粉末衍射、同步加速器X射线衍射和磁性测量研究表明，这种ZTE行为归因于稀土磁矩主导的自发体积磁致伸缩，它可通过可调节的磁相变来控制。目前的工作扩展了ZTE材料家族的范围，并提供了一种探索ZTE材料的有效方法，例如通过调整功能材料家族中与磁性或铁电性相关的相变来实现。
