title: Stabilization of LnB12(Ln = Gd, Sm, Nd, and Pr) in Zr1-xLnxB12under Ambient Pressure.
abstract: We report ambient pressure stabilization of a previously synthesized high-pressure (6.5 GPa) phase, GdB12, in a Zr1-xGdxB12solid 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 ZrB12were also achieved. Previous attempts at preparing these rare-earth borides were unsuccessful even under high pressure. On the basis of 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-xGdxB12and Zr1-xSmxB12can 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 Zr0.45Gd0.55B12and Zr0.70Sm0.30B12, the cubic unit cell parameter (a) reached a value of 7.453 and 7.428 Å, respectively, compared to 7.412 Å for pure ZrB12.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA) , Los Angeles, California 90095, United States.
authors.forename: Georgiy
authors.initials: G
authors.lastname: Akopov
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA) , Los Angeles, California 90095, United States.
authors.forename: Zachary C
authors.initials: ZC
authors.lastname: Sobell
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA) , Los Angeles, California 90095, United States.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Yeung
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA) , Los Angeles, California 90095, United States.|Department of Materials Science and Engineering, University of California, Los Angeles (UCLA) , Los Angeles, California 90095, United States.|California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA) , Los Angeles, California 90095, United States.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Kaner