${\mathrm{Yb}}_{14}{\mathrm{ZnSb}}_{11}$: Charge Balance in Zintl Compounds as a Route to Intermediate Yb Valence

The results of thermodynamic, transport, and x-ray diffraction measurements of single crystals of the new compound ${\mathrm{Yb}}_{14}{\mathrm{ZnSb}}_{11}$ are presented. These data indicate an intermediate Yb valence scenario, with a spin fluctuation temperature of approximately 85 K. The compound is weakly metallic and is isostructural with the charge-balanced Zintl compound ${\mathrm{Yb}}_{14}{\mathrm{AlSb}}_{11}$. The intermediate Yb valence can be qualitatively accounted for by considering the charge counting arguments of the nonmetallic parent, and charge balance in Zintl-related materials appears to be a viable route to designing other compounds with intermediate valence constituents.