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We present magnetization, specific heat, and $^{27}\mathrm{Al}$ NMR investigations on ${\mathrm{YbFe}}_{2}{\mathrm{Al}}_{10}$ over a wide range in temperature and magnetic field. The magnetic susceptibility at low temperatures is strongly enhanced at weak magnetic fields, accompanied by a $\mathrm{ln}({T}_{0}/T)$ divergence of the low-$T$ specific heat coefficient in zero field, which indicates a ground state of correlated electrons. From our hard-x-ray photoemission spectroscopy study, the Yb valence at 50 K is evaluated to be 2.38. The system displays valence fluctuating behavior in the low to intermediate temperature range, whereas above 400 K, ${\mathrm{Yb}}^{3+}$ carries a full and stable moment, and Fe carries a moment of about $3.1{\ensuremath{\mu}}_{B}$. The enhanced value of the Sommerfeld-Wilson ratio and the dynamic scaling of the spin-lattice relaxation rate divided by $T[^{27}(1/{T}_{1}T)]$ with static susceptibility suggests admixed ferromagnetic correlations. $^{27}(1/{T}_{1}T)$ simultaneously tracks the valence fluctuations from the $4f$ Yb ions in the high temperature range and field dependent antiferromagnetic correlations among partially Kondo screened Fe $3d$ moments at low temperature; the latter evolve out of an Yb $4f$ admixed conduction band.

We present magnetization, specific heat, and (27)Al NMR investigations on YbFe2Al10 over a wide range in temperature and magnetic field. The magnetic susceptibility at low temperatures is strongly enhanced at weak magnetic fields, accompanied by a ln(T0/T) divergence of the low-T specific heat coefficient in zero field, which indicates a ground state of correlated electrons. From our hard-x-ray photoemission spectroscopy study, the Yb valence at 50 K is evaluated to be 2.38. The system displays valence fluctuating behavior in the low to intermediate temperature range, whereas above 400 K, Yb(3+) carries a full and stable moment, and Fe carries a moment of about 3.1 μB. The enhanced value of the Sommerfeld-Wilson ratio and the dynamic scaling of the spin-lattice relaxation rate divided by T[(27)(1/T1T)] with static susceptibility suggests admixed ferromagnetic correlations. (27)(1/T1T) simultaneously tracks the valence fluctuations from the 4f Yb ions in the high temperature range and field dependent antiferromagnetic correlations among partially Kondo screened Fe 3d moments at low temperature; the latter evolve out of an Yb 4f admixed conduction band.