We report ambient pressure stabilization of a previously synthesized high-pressure (6.5 GPa) phase, GdB12, in a Zr1-xGdxB12 solid solution (with ~54 at. % Gd solubility, as determined by both powder X-ray diffraction and energy-dispersive spectroscopy). Limited solubilities of Sm (~15 at. % Sm), Nd (~7 at. % Nd) and Pr (~4 at. % Pr) in ZrB12 was also achieved. Previous attempts at preparing these rare-earth borides were unsuccessful even under high pressure. Based on insights provided from the unit cell sizes observed via solid solutions, at least 6.5 GPa of pressure would be needed to synthesize these rare-earth borides since Sm, Nd and Pr atomic radii are larger than that of Gd. The solid-solution formation for Zr1-xGdxB12 and Zr1-xSmxB12 can be seen in the change of the unit cell of each of the solid solutions relative to their pure parent compounds as well as in the change of color of the respective alloys. For Zr0.45Gd0.55B12 and Zr0.70Sm0.30B12, the cubic unit cell parameter (a) reached a value of 7.453 Å and 7.428 Å, respectively, compared to 7.412 Å for pure ZrB12.

Stabilization of GdB12 in Zr1-xGdxB12 under ambient pressure

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.