论文标题
Cual2型超导体COZR2中的异常热膨胀
Anomalous thermal expansion in a CuAl2-type superconductor CoZr2
论文作者
论文摘要
在这项工作中，我们表明Cual2型超导体COZR2和合金系统在较大温度范围内表现出异常的热膨胀。我们在COZR2上进行了中子粉末衍射和X射线粉末衍射，并观察到了各向异性热膨胀，c轴的负热膨胀常数为αc<-15μk-1在t = 50-573 k的宽温度范围内，温度降低，同时c n = 50-573 k。 Co-ZR键的较小变化以及ZR-CO-ZR角的系统下降来解释A轴/C轴各向异性收缩/膨胀的起源。在合金的系统（Fe，Co，ni）Zr2和（Fe，Co，ni，rh，ir）Zr2中观察到类似的热膨胀，这表明该现象在TRZR2系统中是常见的特征。我们建议通过优化TRZR2中A轴和C轴的对比度膨胀来实现零热膨胀金属。
In this work, we show that the CuAl2-type superconductor CoZr2 and alloyed systems exhibit anomalous thermal expansion in a wide temperature range. We performed neutron powder diffraction and X-ray powder diffraction on CoZr2 and observed remarkably anisotropic thermal expansion with a c-axis negative thermal expansion constant of αc < -15 μK-1 in a wide temperature range of T = 50-573 K. With decreasing temperature, the lattice constant a decreases, while the lattice constant c continuously increases in CoZr2. The origin of the anisotropic shrinkage/expansion of the a-axis/c-axis by cooling is explained by the small change in the Co-Zr bond and the systematic decrease in the Zr-Co-Zr angle. Similar thermal expansion was observed in alloyed systems, (Fe,Co,Ni)Zr2 and (Fe,Co,Ni,Rh,Ir)Zr2, which suggests that the phenomenon is common feature in the TrZr2 system. We propose that zero-thermal expansion metals would be achieved by optimizing the contrasting thermal expansion of a-axis and c-axis in TrZr2.
