The Ni–Bi intermetallic system contains compounds with properties such as superconductivity and ferromagnetism. While these compounds are stable under ambient conditions, there could be other, high-pressure phases with interesting and useful properties.

Danna E. Freedman, Northwestern University, Evanston, IL, USA, and colleagues have discovered a new high-pressure phase in the Ni–Bi system, β-NiBi. The team used a laser heated diamond anvil cell (LHDAC) to prepare the new phase from α-NiBi powder at 700 °C under about 37 GPa of pressure. The reaction was observed using in situ powder X-ray diffraction (PXRD).

The discovered phase crystallizes in a modification of the TlI structure type, a first for binary pnictide compounds. It remains stable down to ca. 11.6 GPa and reconverts to α-NiBi at lower pressures.

• High-pressure discovery of β-NiBi,
  Kelly M. Powderly, Samantha M Clarke, Maximilian Amsler, Chris M Wolverton, Christos D. Malliakas, Yue Meng, Steven D. Jacobsen, Danna Freedman,
  Chem. Commun. 2017.
  DOI: 10.1039/C7CC06471C