Synthesis and Electrical Properties of a New Compound (BiSe)0.97(Bi2Se3)1.26(BiSe)0.97(MoSe2) Containing Metallic 1T-MoSe2

Choffel, Marisa A.; Gannon, Renae N.; Göhler, Fabian; Miller, Aaron M.; Medlin, Douglas L.; Seyller, Thomas; Johnson, David C.

doi:10.1021/acs.chemmater.1c01623

Cited by 8 publications

(1 citation statement)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One approach used for the synthesis of complex ternary phases is to avoid the formation of these binary intermediates altogether. − By depositing the elements into a thin, ordered film, the diffusion path length of all of the elements can be minimized. As this ordered amorphous film is then annealed, the layers react and directly form the desired ternary product with very high purity.…”

Section: Resultsmentioning

confidence: 99%

2 + 2 = 3: Making Ternary Phases through a Binary Approach

et al. 2022

View full text Add to dashboard Cite

Synthetic organic chemists have a large toolbox of named reactions to form structural motifs through a retrosynthetic approach when targeting a complex molecule. On the other hand, a comparatively complex inorganic compound may be made through simple mechanochemical reactions of the elements followed by annealing. For complex phases that involve more than two elements, the simple mechanochemical process can be complex with many competing phases, which can negatively impact desired properties. This point has been made recently with a revelation of improved properties of thermoelectric materials upon the removal of impurities. Compounds of the Yb14AlSb11 structure type represent complex Zintl phases with exceptional high-temperature thermoelectric properties but are difficult to prepare in high purity. In this work, a quenching study was used to elucidate the pathway taken by reactions from the elements to form the complex ternary phase, Yb14AlSb11. Through that study, two Yb–Sb binary phases, Yb11Sb10 and Yb4Sb3, were identified as intermediates in the reaction. These two Yb–Sb binaries were investigated for use as reactive precursors to form Yb14MnSb11 in reactions with MnSb. Through this pseudoretrosynthetic approach, reactions from Yb4Sb3 allowed for the synthesis of high-purity Yb14MnSb11 and Yb14MgSb11 through balanced, stoichiometric reactions. The apparent Yb2O3 (∼1%) impurity found in these products was systematically reduced with x in the series Yb14‑x MnSb11 (x = 0–0.05), suggesting that the main phase is inherently Yb-deficient and showing the high degree of control obtained through this synthetic approach. The stoichiometric sample of Yb14MgSb11 has a peak zT of 1.3 at 1175 K, and the stoichiometric sample of Yb14MnSb11 has a peak zT of 1.2 at 1275 K. This approach to solid-state synthesis provides reproducible products from balanced stoichiometric reactants to form high-purity complex structure types and can be adapted to other difficult ternary systems.

show abstract