Bistructural Pseudocontinuous Solid Solution with Hierarchical Microstructures from Ab initio Study: Application to the Mg2Sn-Mg3Sb2 System

Dong, Erting1,2; Zhu, Yongbin3; Tan, Shihua4; Liu, Weishu3; Wang, Jiong5; Zhang, Wenqing3,6,7

2022-09-01

10.1016/j.actamat.2022.118139

ACTA MATERIALIA   影响因子和分区

1359-6454

1873-2453

Hetero-structural solid solutions, i.e. those from the parent compounds with different crystal structures, occasionally appear for exploring new materials, but a systematic understanding of the thermodynamics, microstructures and electronic characteristics is still lacking. By alloying cubic (1-x)Mg2Sn with hexagonal (0.5x)Mg3Sb2, we show that such a system manifests an overall pseudocontinuous composition distribution with hierarchical microstructures, and the coexistence of n-type/p-type electronic conduction regions. This type of solid solution is defined as a bistructural pseudocontinuous solid solution (BiSS), clearly different from the homogenous iso-structural solid solutions. The Mg2-0.5xSn1-xSbx phase is found to be stable at the Mg2Sn-based phase only in the range of 0 < x <= similar to 0.47, consistent with experimental observations. Large-scale Monte Carlo simulations reveal the natural occurrence of hierarchical microstructures, which contains primarily both nanoscale Mg-deficiency clusters and a homogeneous matrix showing tunable compositions relevant to alloy composition and annealing temperature. The electronic structures of the BiSS thus manifest a spatially inhomogeneous coexistence of n-type matrix and p-type nanoclusters, implying the importance of selective doping for optimizing thermoelectric performance. Those phenomena could be considered universal in hetero-structural solid solutions. This work offers a general guideline for the design of bistructural and even hetero-structural solid solutions with potential novel functionality. (C) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

bistructural pseudocontinuous solid solution hetero-structural solid solution hierarchical microstructure electronic structure

SCI

英语

通讯

National Key R&D Program of China[2019YFA0704901] ; Natural Science Foundation of China["92163212","51872133"] ; Shenzhen Municipal Key-Lab program[ZDSYS20190902092905285] ; Guangdong Provincial Key Laboratory of Computational Science and Material Design[2019B030301001] ; Guangdong Innovation Research Team Project[2017ZT07C062] ; Natural Science Foundation of China Program[51872133]

Materials Science ; Metallurgy & Metallurgical Engineering

Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering

WOS:000838025900001

PERGAMON-ELSEVIER SCIENCE LTD

MATERIALS SCIENCE

Web of Science

1.Harbin Inst Technol, Harbin 150080, Peoples R China
2.Southern Univ Sci & Technol, Dept Phys, Shenzhen 518055, Peoples R China
3.Southern Univ Sci & Technol, Dept Mat Sci & Engn, Shenzhen 518055, Peoples R China
4.Cent South Univ Forestry & Technol, Hunan Prov Key Lab Mat Surface Interface Sci & Tec, Changsha 410004, Peoples R China
5.Cent South Univ, Powder Met Res Inst, Changsha 410083, Peoples R China
6.Southern Univ Sci & Technol, Shenzhen Municipal Key Lab Adv Quantum Mat & Devic, Shenzhen 518055, Guangdong, Peoples R China
7.Southern Univ Sci & Technol, Guangdong Prov Key Lab Computat Sci & Mat Design, Shenzhen 518055, Guangdong, Peoples R China

Dong, Erting,Zhu, Yongbin,Tan, Shihua,et al. Bistructural Pseudocontinuous Solid Solution with Hierarchical Microstructures from Ab initio Study: Application to the Mg2Sn-Mg3Sb2 System[J]. ACTA MATERIALIA,2022,236.

Dong, Erting,Zhu, Yongbin,Tan, Shihua,Liu, Weishu,Wang, Jiong,&Zhang, Wenqing.(2022).Bistructural Pseudocontinuous Solid Solution with Hierarchical Microstructures from Ab initio Study: Application to the Mg2Sn-Mg3Sb2 System.ACTA MATERIALIA,236.

Dong, Erting,et al."Bistructural Pseudocontinuous Solid Solution with Hierarchical Microstructures from Ab initio Study: Application to the Mg2Sn-Mg3Sb2 System".ACTA MATERIALIA 236(2022).