Role of disorder in the synthesis of metastable zinc zirconium nitrides
Role of disorder in the synthesis of metastable zinc zirconium nitrides
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无序在亚稳态氮化锆锌合成中的作用
DOI：
10.1103/physrevmaterials.6.043804
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发表时间：
2022
影响因子：
3.4
通讯作者：
Zakutayev, Andriy
中科院分区：
文献类型：
--
作者：
Woods-Robinson, Rachel;Stevanović, Vladan;Lany, Stephan;Heinselman, Karen N.;Horton, Matthew K.;Persson, Kristin A.;Zakutayev, Andriy
在材料科学中，通常假设密度泛函理论预测的基态晶体结构是最容易合成的多晶型。三元氮化物材料具有许多可能的亚稳晶型，为研究影响热力学稳定性和晶型合成的因素提供了丰富的材料空间。例如，理论上预测在零开尔文的情况下，将具有一种具有引人注目的光电性能的不同寻常的层状“wurtsalt”基态晶体结构，但目前尚不清楚这种结构能否在实际合成条件下通过实验实现。在这里，我们使用组合溅射法合成了数百个薄膜样品，发现了亚稳的岩盐衍生结构或氮化硼衍生结构，而不是预测的岩盐结构。用统计多晶型取样器方法证明，尽管岩盐在零开尔文时是最不稳定的多晶型，但它在类似于这种溅射沉积方法所获得的高有效温度下成为最稳定的多晶型，从而证实了实验结果。另外的计算表明，wurtsalt多晶型的这种失稳是由于组态的熵和热效应，而振动的贡献可以忽略不计。具体地说，岩盐和氮化硼衍生的结构在无序存在的情况下成为最稳定的多晶型，因为它对阳离子交叉取代和偏离化学计量比的容忍度比岩盐结构高。这种对无序容忍在竞争多态合成中的作用的理解可以使更准确地预测可合成的晶体结构及其可实现的材料性质。
In materials science, it is often assumed that ground-state crystal structures predicted by density functional theory are the easiest polymorphs to synthesize. Ternary nitride materials, with many possible metastable polymorphs, provide a rich materials space to study what influences thermodynamic stability and polymorph synthesizability. For example,is theoretically predicted at zero Kelvin to have an unusual layered “wurtsalt” ground-state crystal structure with compelling optoelectronic properties, but it is unknown whether this structure can be realized experimentally under practical synthesis conditions. Here, we use combinatorial sputtering to synthesize hundreds ofthin-film samples, and find metastable rocksalt-derived or boron-nitride-derived structures rather than the predicted wurtsalt structure. Using a statistical polymorph sampler approach, it is demonstrated that although rocksalt is the least stable polymorph at zero Kelvin, it becomes the most stable polymorph at high effective temperatures similar to those achieved using this sputter deposition method, and thus corroborates experimental results. Additional calculations show that this destabilization of the wurtsalt polymorph is due to configurational entropic and enthalpic effects, and that vibrational contributions are negligible. Specifically, 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. This understanding of the role of disorder tolerance in the synthesis of competing polymorphs can enable more accurate predictions of synthesizable crystal structures and their achievable material properties.
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稳定和亚稳定三元氮氧化物的计算发现。
DOI：
10.1063/5.0050356
发表时间：
2021
期刊：
The Journal of chemical physics
影响因子：
--
作者：
A. Sharan;S. Lany
通讯作者：
S. Lany
利用高压复分解反应合成新型岩盐型三元氮化物半导体 MgSnN2
影响因子：
2.3
作者：
F. Kawamura;M. Imura;H. Murata;N. Yamada;T. Taniguchi
通讯作者：
T. Taniguchi
影响因子：
6.1
作者：
Jain, Anubhav;Shyue Ping Ong;Persson, Kristin A.
通讯作者：
Persson, Kristin A.
影响因子：
4
作者：
Scanlon, David O.;Watson, Graeme W.
通讯作者：
Watson, Graeme W.
影响因子：
8.6
作者：
V. Stevanović
通讯作者：
V. Stevanović