Nelson W L, Chemey A T, Hertz M, Choi E, Graf D E, Latturner S, Albrecht-Schmitt T E, Wei K, Baumbach R E
National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA.
Department of Physics, Florida State University, Tallahassee, FL, 32306, USA.
Sci Rep. 2020 Mar 13;10(1):4717. doi: 10.1038/s41598-020-61666-z.
High entropy alloys (HEA) are an unusual class of materials where mixtures of elements are stochastically arrayed on a simple crystalline lattice. These systems exhibit remarkable functionality, often along several distinct axes: e.g., the examples TaNb are high strength and damage resistant refractory metals that also exhibit superconductivity with large upper critical fields. Here we report the discovery of an f-electron containing HEA, TaNb, which is the first to include an actinide ion. Similar to the Zr-analogue, this material crystallizes in a body-centered cubic lattice with the lattice constant a = 3.41(1) Å and exhibits phonon mediated superconductivity with a transition temperatures T ≈ 3.2 K and upper critical fields H ≈ 6.4 T. These results expand this class of materials to include actinide elements, shows that superconductivity is robust in this sub-group, and opens the path towards leveraging HEAs as functional waste forms for a variety of radioisotopes.
高熵合金（HEA）是一类特殊的材料，其中元素混合物随机排列在简单的晶格上。这些体系展现出显著的功能特性，通常体现在几个不同方面：例如，TaNb 这类材料是高强度且抗损伤的难熔金属，同时还表现出具有高上临界场的超导性。在此，我们报告发现了一种含 f 电子的高熵合金 TaNb，这是首个包含锕系离子的高熵合金。与锆类似物相似，这种材料结晶为体心立方晶格，晶格常数 a = 3.41(1) Å，并表现出声子介导的超导性，其转变温度 T ≈ 3.2 K，上临界场 H ≈ 6.4 T。这些结果将这类材料扩展到包含锕系元素，表明超导性在该子组中很稳定，并为将高熵合金用作多种放射性同位素的功能性废物形式开辟了道路。
