紊乱在三亚氮化物合成中的作用(CS)

雷切尔·伍兹-罗宾森、弗拉丹 ·斯特瓦诺维奇、斯蒂芬·拉尼、卡伦·海因塞尔曼、克里斯汀·佩尔松、安德烈·扎库塔耶夫

在材料科学中，人们通常认为最热力学稳定的晶体结构是最容易合成的多态体。三元氮化物材料，有许多可能的变质多态性，提供了一个域来测试这一假设;例如，ZnZrN2预计将具有不寻常的分层"wurtsalt"晶体结构和令人兴奋的光电特性，但它能否在实验中实现？在这里，我们合成了数百个ZnxZr1= x Ny薄膜样本，并找到元稳定岩盐衍生或氮化氮衍生结构，而不是热力学稳定的武盐结构。计算表明，这种背离是由于热带和昆虫稳定的影响。 Rocksalt- 和氮氮化物衍生结构成为无序的存在状态下最稳定的多态体，这是因为更高的公差阳离子交叉替代和离植物学比武尔特盐结构。通过了解无序容差在元易多态合成中的作用，我们可以更准确地预测可合成晶体结构及其可实现的物质特性。

The role of disorder in the synthesis of metastable ternary nitrides

Rachel Woods-Robinson, Vladan Stevanović, Stephan Lany, Karen Heinselman, Kristin A. Persson, Andriy Zakutayev

In materials science, it is often assumed that the most thermodynamically stable crystal structure is the easiest polymorph to synthesize. Ternary nitride materials, with many possible metastable polymorphs, provide a domain to test this assumption; for example, ZnZrN2 is predicted to have an unusual layered "wurtsalt" crystal structure and exciting optoelectronic properties, but can it be realized experimentally? Here, we synthesize hundreds of ZnxZr1−xNy thin film samples, and find metastable rocksalt-derived or boron-nitride-derived structures rather than the thermodynamically stable wurtsalt structure. Computations show that this divergence is due to both entropic and enthalpic stabilization effects. Rocksalt- and boron-nitride-derived structures become the most stable polymorphs in the presence of disorder because of higher tolerances to cation cross-substitution and off-stoichiometry than the wurtsalt structure. By understanding the role of disorder tolerance in the synthesis of metastable polymorphs, we can enable more accurate predictions of synthesizable crystal structures and their achievable material properties.