Atomic size mismatch: What if it is too large?

Other than facilitating phase separation that is often the case, large atomic size mismatch may elicit bulk metallic glasses, crystalline line compounds, or solid solution-like single phases of matter with exquisite structures and application-pertinent properties. The properties a material largely follow its structure: e.g., whether single- multi-phased, structure long-range short-range ordered. Doping alloying most effective way to tailor material’s In process doping alloying, should one factor be merely allowed explain maximum intuitiveness likelihood, it will mismatch. As shown in Figure 1, classic Hume-Rothery rules1Hume-Rothery W. Powell H.M. On theory super-lattice alloys.Z. Krist-Cryst. Mater. 1935; 91: 23-47Crossref Google Scholar states difference between solute solvent atom needs no more 15% form single-phased solution—above solubility-limit phase, occurs as result enthalpy being undercompensated by entropy. diagrams mismatched compounds such PbS-PbTe,2Doak J.W. Wolverton C. Coherent incoherent stabilities thermoelectric rocksalt IV-VI semiconductor alloys.Phys. Rev. B. 2012; 86: 144202Crossref Scopus (39) GaP-GaSb, ZnO-ZnTe3Zhang X. Trimarchi G. d’Avezac M. Zunger A. Long-range order instead lattice-mismatch isovalent AX−BX systems.Phys. 2009; 80: 241202Crossref (6) are good examples this regard. hand, larger generally yields lower solubility limit (Figure squares pentagons). other outcome but not sole outcome. main theme preview revolves around possible outcomes mismatch—namely, matter. Inoue criterion4Inoue Stabilization supercooled liquid amorphous alloys.Acta 2000; 48: 279-306Crossref (5233) an significantly 12% along exothermic heat mixing favor formation glass over solution from multinary triangles). quaternary heterovalent perovskite oxides, lattice constant suppresses through forming superlattice-type spontaneous ordering [110] direction.5Caetano Butler K.T. Walsh Analysis electrostatic stability solutions.Phys. 2016; 93: 144205Crossref (8) Zhang et al. reported BeO BaO LiF CsF led which was lowered coordination number disproportionation, despite Be (1.05 Å) Ba (2.15Å) Li (1.45 Cs (2.60 stars).3Zhang separation, several recent articles novel wide composition range spheres). Compared small-size-mismatched solutions context rules, these large-size-mismatched synthesized similar recipes exhibit extraordinary For example, He obtained full Cu2S Cu2Te using routine melting-annealing technique Te having much radius (1.40 S (1.00 Å).6He Y. Lu P. Shi Xu F. T. Snyder G.J. Uher Chen L. Ultrahigh Thermoelectric Performance Mosaic Crystals.Adv. 2015; 27: 3639-3644Crossref PubMed (174) A nanoscale mosaic-crystal microstructure observed found stable up nearly 1,000 K. Similar microstructures were only previously special flash-cooling technique. Alloying semiconductors Ag2S Ag2Te via rare coexistence structural characteristics, exceptional mechanical flexibility, superior performance.7He S. Liu Jiang Feng J. Zhu Dong Z. Deng Luo al.Semiconductor flexibility high room temperature performance.Sci. Adv. 2020; 6: eaaz8423Crossref (41) Single-phased Mg2Si Mg2Sn attained two-stage solid-state reaction entire highly Si (1.10 Sn Å).8Liu Tan Yin H. Tang al.Convergence conduction bands means enhancing performance n-type Mg2Si(1-x)Sn(x) Lett. 108: 166601Crossref (930) Ponnambalam P Mg3(Bi,P)2 prepared method 25%, though Bi 37%.9Ponnambalam V. Morelli D.T. Zintl Mg3Bi2-xPnx (Pn = Sb).J. Electron. 2013; 42: 1307-1312Crossref (56) Note can simultaneously implemented on both cationic anionic sites. Zhao discovered series (Cu1-xAgx)2(Te1-ySy) fairly range.10Zhao Eikeland E. D. Qiu Jin Song Q. Wei al.Thermoelectric materials crystal-amorphicity duality induced mismatch.Joule. 2021; 5: 1183-1195Abstract Full Text PDF (9) featured unique crystal any binary ternary (Cu/Ag)2(S/Te) compounds. Atomic worth attention further utilization research. Notwithstanding above presented portfolio rich well interesting properties, questions remain concerning role interplay factors structure. example:(1)What diagram at junction rules criterion terms mismatch?(2)How does large-atomic-size-mismatched cope stress range?(3)Is there inherent link characteristics mosaic-crystal, given synthesis involve fast cooling? These delineate where research gaps also paradigm-shifting discoveries expected future acknowledges support National Natural Science Foundation China (NSFC) under grant no. 51625205 . NSFC 52072388 We thank Prof. L.D. for helpful discussions. data points metal alloys 1 derived ASM Alloy Phase Diagram Database: https://www.asminternational.org/materials-resources/online-databases/-/journal_content/56/10192/15469013/DATABASE. mismatchZhao al.JouleApril 16, 2021In BriefThe (Cu1−xAgx)2(Te1−ySy), 0.16 ≤ x 0.24 y 0.24, adopt complex orthorhombic S/Te mismatch-induced duality. leads extremely low thermal conductivities zT values ∼2.0 Full-Text Open Archive