La4 Co4 X (X=Pb, Bi, Sb) : A demonstration of antagonistic pairs as a route to quasi-low-dimensional ternary compounds

Journal Article · Mon Jun 03 00:00:00 EDT 2024 · Physical Review Materials

DOI:https://doi.org/10.1103/physrevmaterials.8.064401· OSTI ID:2376182

Slade, Tyler J. ^[1]; Furukawa, Nao ^[1]; Dygert, Matthew ^[2]; Mohamed, Siham ^[1]; Das, Atreyee ^[1]; Xia, Weiyi ^[1]; Wang, Cai-Zhuang ^[1]; Bud'ko, Sergey L. ^[1]; Canfield, Paul C. ^[1]

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1. Ames Lab., and Iowa State Univ., Ames, IA (United States)
2. Ames Lab., and Iowa State Univ., Ames, IA (United States); Univ. of Missouri, Columbia, MO (United States)

We outline how pairs of strongly immiscible elements, referred to here as antagonistic pairs, can be used to synthesize ternary compounds with low or quasi-reduced-dimensional motifs intrinsically built into their crystal structures. By identifying third elements that are mutually compatible with a given antagonistic pair, ternary compounds can be formed in which the third element segregates the immiscible atoms into spatially separated substructures. Quasi-low-dimensional structural units, such as sheets, chains, or clusters are a natural consequence of the immiscible atoms seeking to avoid close contact in the solid state. Further, as proof of principle, we present the discovery, crystal growth, and basic physical properties of La₄⁢Co₄⁢$$\mathrm{X}$$ (X = Pb, Bi, Sb), a family of intermetallic compounds based on the antagonistic pairs Co-Pb and Co-Bi. La₄⁢Co₄⁢$$\mathrm{X}$$ adopts an orthorhombic crystal structure (space group Pbam) containing quasi-two-dimensional Co slabs and La-X polyhedra that stack in an alternating manner along the α axis. Consistent with our proposal, the La atoms separate the Co and X substructures, ensuring there are no direct contacts between the members of the immiscible (antagonistic) pair. Within the Co slabs, the atoms occupy the vertices of corner sharing tetrahedra and triangles, and this bonding motif produces narrow electronic bands near the Fermi level that favor magnetism. The Co is moment bearing in each La₄⁢Co₄$$\mathrm{X}$$ compound studied, and we show that whereas La₄⁢Co₄⁢Pb behaves as a three-dimensional antiferromagnet with T_N=220K, La₄⁢Co₄⁢Bi and La_4⁢Co₄⁢Sb have behavior consistent with low-dimensional magnetic coupling and ordering, with T_N=153K and 143 K, respectively. In addition to the Pb-, Bi-, and Sb-based La₄⁢Co₄⁢$$\mathrm{X}$$ compounds, we also were likely able to produce an analogous La₄⁢Co₄⁢Sn in polycrystalline form, although we were unable to isolate single crystals. We anticipate that identifying and using mutually compatible third elements together with an antagonistic pair represents a generalizable design principle for discovering new materials and new structure types containing low-dimensional substructures.

• Research Organization: Ames Laboratory (AMES), Ames, IA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE); USDOE Office of Science (SC), Workforce Development for Teachers and Scientists (WDTS)
• Grant/Contract Number: AC02-07CH11358
• OSTI ID: 2376182
• Alternate ID(s): OSTI ID: 2474100
• Report Number(s): IS-J--11,359
• Journal Information: Physical Review Materials, Journal Name: Physical Review Materials Journal Issue: 6 Vol. 8; ISSN 2475-9953
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE