Synthesis, structure, and magnetic and electrical properties of Yb(Mn,M)xAl12-x (M = Fe, Ru; X ≤ 2.5) phases

Single crystals of Yb(Mn,M)xAl12-x (M = Fe, Ru; x ≤ 2.5) were grown utilizing an aluminum self-flux. Products crystallized in three structure types, the ThMn12 structure type, and two structural derivatives, the CaCr2Al10 structure type and the YbFe2Al10 structure type, depending on the starting amount of Mn relative to M. We outline the synthetic parameters used to obtain products in all three structure types and specifically address how stabilizing products in one structure type over another is a function of Mn:M reaction ratios. All compounds are structurally characterized with single crystal X-ray diffraction, and Yb(Mn,Fe)xAl12-x compounds are additionally characterized with temperature-dependent magnetic susceptibility and resistivity measurements. Yb(Mn,Fe)xAl12-x compounds exhibit paramagnetic behavior down to 2 K, as well as metallic resistivity down to ∼50 K. Below 50 K, Yb(Mn,Fe)xAl12-x compounds exhibit upturns in resistivity that indicate the onset of Kondo interactions. © 2013 American Chemical Society