论文标题
高渗透稀土四边形
High-Entropy Rare Earth Tetraborides
论文作者
论文摘要
第一次成功合成了四方UB4型结构的六个高渗透稀土四核苷。样品是通过高能量球磨机和原位反应性火花等离子体烧结从元素前体制备的。烧结的标本的相对密度> 98％，没有可检测到的氧化物杂质（尽管在某些组成中存在较小的六核酸酯）。在组合中未观察到可检测的次级阶段（y $ _ {0.2} $ nd $ _ {0.2} $ sm $ $ _ {0.2} $ gd $ _ {0.2} $ _ {0.2} $ _ {0.2} $ _ {0.2} $ _ {0.2} $） Vickers的微标志在9.8 N的标准压痕负载下确定为〜13-15 GPA。科学有趣的观察结果由各向异性晶格扭曲与混合规则平均值表示。这项工作通过制造一类新的高渗透式硼化物来扩展高渗透陶瓷的家族，并具有独特的四方准层晶体结构。
Six high-entropy rare earth tetraborides of the tetragonal UB4-prototyped structure have been successfully synthesized for the first time. The specimens are prepared from elemental precursors via high-energy ball mill and in-situ reactive spark plasma sintering. The sintered specimens are >98% in relative densities without detectable oxide impurities (albeit the presence of minor hexaborides in some compositions). No detectable secondary phase is observed in the composition (Y$_{0.2}$Nd$_{0.2}$Sm$_{0.2}$Gd$_{0.2}$Tb$_{0.2}$)B$_{4}$, which is proven homogeneous at both microscale and nanoscale. The Vickers microhardness are determined to be ~13-15 GPa at a standard indentation load of 9.8 N. A scientifically interesting observation is represented by the anisotropic lattice distortion from the rule-of-mixture averages. This work expands the family of high-entropy ceramics via fabricating a new class of high-entropy borides with a unique tetragonal quasi-layered crystal structure.
