Adjustable Magnetic Phase Transition Inducing Unusual Zero Thermal Expansion in Cubic RCo2-Based Intermetallic Compounds (R = Rare Earth)
Adjustable Magnetic Phase Transition Inducing Unusual Zero Thermal Expansion in Cubic RCo2-Based Intermetallic Compounds (R = Rare Earth)
复制标题
可调节磁相变在立方 RCo2 基金属间化合物（R = 稀土）中引起异常的零热膨胀
DOI：
10.1021/acs.inorgchem.9b00480
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发表时间：
2019-05-06
影响因子：
4.6
通讯作者：
Xing, Xianran
中科院分区：
文献类型：
--
作者：
Hu, Jinyu;Lin, Kun;Xing, Xianran
热膨胀或零热膨胀(ZTE)的金属材料在实际应用中具有很大的优点，但这些材料很少，而且它们的热膨胀很难控制。在这里，我们成功地将一系列(Gd，R)(Co，Fe)(2)(R=Dy，Ho，Er)金属间化合物的热膨胀行为从强烈但突然的负调整到了宽温度范围内的零，方法是通过调整组成使一级磁相变变为二级。有趣的是，在10-275K的温度范围内，立方Gd(0.25)Dy(0.75)Co(1.93)Fe0.07(GDCF)的热膨胀系数为α(1)=0.16(0)×10(-6)K-1，获得了一种特殊的各向同性ZTE性质。短波长中子粉衍射、同步X射线衍射和磁测量研究表明，这种ZTE行为归因于稀土矩主导的自发体积磁致伸缩，这种自发体积磁致伸缩可以通过可调节的磁相变来控制。本工作扩展了中兴通讯家族的范围，并为探索中兴通讯材料提供了一种有效的方法，例如通过调整功能材料家族中与磁性或铁电相关的相变。
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)(2) (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 alpha(1)= 0.16(0) x 10(-6) K-1 was achieved in cubic Gd(0.25)Dy(0.75)Co(1.93)Fe0.07 (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.