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Synthesis, Crystal and Electronic Structure of the Titanium Bismuthides Sr 5 Ti 12 Bi 19+ x , Ba 5 Ti 12 Bi 19+ x , and Sr 5– δ Eu δ Ti 12 Bi 19+ x ( x ≈ 0.5–1.0; δ ≈ 2.4, 4.0)
Author(s) -
Ovchinnikov Alexander,
Bobev Svilen
Publication year - 2018
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201701426
Subject(s) - crystallography , chemistry , crystal structure , octahedron , ternary operation , magnetization , electrical resistivity and conductivity , titanium , physics , organic chemistry , quantum mechanics , computer science , magnetic field , programming language
Crystals of the new ternary bismuthides AE 5 Ti 12 Bi 19+ x ( AE = Sr, Ba) and Sr 5– δ Eu δ Ti 12 Bi 19+ x ( δ ≈ 2.4, 4.0; x ≤ 1.0) were grown using an excess of molten Bi as a flux. The title compounds crystallize in the cubic non‐centrosymmetric space group P 4 3 m and are structurally related to the antimonides Ba 5 M 12 Sb 19+ x ( M = Ti, V, Nb). The crystal structure features Ti atoms stuffed in the γ‐brass‐like sub‐lattice made of AE ( AE = Sr, Ba, Eu) and Bi atoms. The arrangement of the AE atoms, on its own, represents a framework consisting of interconnected regular tetrahedra and octahedra. Another notable attribute of the AE 5 Ti 12 Bi 19+ x structure is the disordered Bi moiety located at the center of the unit cell and showing homoatomic Bi–Bi bonding. Electronic structure calculations and electrical resistivity measurements indicate metallic behavior of the new bismuthides. Magnetization measurements on samples of Sr 5– δ Eu δ Ti 12 Bi 19+ x show paramagnetic behavior consistent with the 2+ ground state for Eu. The measurements also confirm no magnetic ordering down to 3 K, stemming from the geometrically frustrated exchange interactions of the Eu 2+ cations.