Cagelike Diamondoid Nitrogen at High Pressures
Cagelike Diamondoid Nitrogen at High Pressures
复制标题
高压下的笼状金刚石氮
DOI：
10.1103/physrevlett.109.175502
复制
发表时间：
2012-10-24
影响因子：
8.6
通讯作者：
Ma, Yanming
中科院分区：
文献类型：
--
作者：
Wang, Xiaoli;Wang, Yanchao;Ma, Yanming
在高压下，三键分子氮分解为单键聚合物氮，这是一种潜在的高能量密度材料。聚合氮的稳定高压形式的发现引起了极大的兴趣。我们报道了通过第一性原理结构搜索预测的笼状钻石状氮在高压下的显著稳定性。聚合物氮的类金刚石结构在其他元素中都没有发现，它采用高度对称的体心立方结构，晶位由类金刚石占据，每个类金刚石由10个氮原子组成，形成一个N-10四环笼状结构。在所有已知的聚合物结构中，金刚烷氮具有较宽的能隙，在263 Gpa以上的聚合物结构中能量最稳定，这一压力可以通过高压实验获得。我们的发现是朝着理解固体氮在极端条件下的行为迈出的重要一步。
Under high pressure, triply bonded molecular nitrogen dissociates into singly bonded polymeric nitrogen, a potential high-energy-density material. The discovery of stable high-pressure forms of polymeric nitrogen is of great interest. We report the striking stabilization of cagelike diamondoid nitrogen at high pressures predicted by first-principles structural searches. The diamondoid structure of polymeric nitrogen has not been seen in any other elements, and it adopts a highly symmetric body-centered cubic structure with lattice sites occupied by diamondoids, each of which consists of ten nitrogen atoms, forming a N-10 tetracyclic cage. Diamondoid nitrogen possesses a wide energy gap and is energetically most stable among all known polymeric structures above 263 GPa, a pressure that is accessible to a high-pressure experiment. Our findings represent a significant step toward the understanding of the behavior of solid nitrogen at extreme conditions.