Crystal Structures, Superconducting Properties, and the Coloring Problem in ReAlSi and ReGaSi

Victoria Decocq; Xin Gui; Alec Neeson; Weiwei Xie; Thomas Heitmann; Fei Wang

doi:10.1021/acs.inorgchem.0c02578

Crystal Structures, Superconducting Properties, and the Coloring Problem in ReAlSi and ReGaSi

Inorg Chem. 2020 Dec 7;59(23):17310-17319. doi: 10.1021/acs.inorgchem.0c02578. Epub 2020 Nov 16.

Authors

Victoria Decocq¹, Xin Gui², Alec Neeson¹, Weiwei Xie^{2

3}, Thomas Heitmann⁴, Fei Wang¹

Affiliations

¹ Department of Chemistry, Missouri State University, Springfield, Missouri 65897, United States.
² Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States.
³ Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, United States.
⁴ ̂MU Research Reactor, University of Missouri, Columbia, Missouri 65211, United States.

PMID: 33196175
DOI: 10.1021/acs.inorgchem.0c02578

Abstract

The only nonsuperconducting rhenium-silicon binary compound, ReSi_1.75, was heavily p-doped with Ga and Al into ReGaSi and ReAlSi in an attempt to evoke superconductivity. They were synthesized and their crystal structures were studied by both X-ray and neutron diffraction. Si and Ga/Al atoms are ordered into alternating layers, which was rationalized with the "coloring problem" study via first-principles calculations. ReGaSi cannot be further p-doped with more Ga, but ReAlSi can be doped with more Al to ReAl_1.2Si_0.8, in which Si and Al atoms are not ordered but randomly distributed on the same sites. The superconductivity measurements over these compounds demonstrate that the ordered ReAlSi and ReGaSi are not bulk superconductors. However, ReAl_1.2Si_0.8 becomes bulk superconductor with T_c = ∼3.5 K, which has been confirmed by magnetism, resistivity, and specific heat measurements.