We present measurements of the magnetization $M$, ac susceptibility ${\chi }^{\prime }$, electrical resistivity $\rho$, and specific heat $C$ in single crystals of metallic YFe${}_2$Al${}_{10}$. The magnetic susceptibility follows a Curie-Weiss temperature dependence for $75\text{K}\le T\le 750$ K, with a fluctuating Fe moment of 0.45${\mu }_B$/Fe, and the ac susceptibility ${\chi }^{\prime }$ diverges at lower temperatures ${\chi }^{\prime }\sim T^{-1.28\pm 0.04}$ when the ac field is in the basal plane. The field $B$ and temperature $T$ dependencies of the magnetization $M$ are well described by the scaling expression $M{T}^{-\beta }$ $=$ $\mathcal{F}$($B$/$T$${}^{\beta +\gamma }$) for $1.8\text{K}\le T\le 30$ K and for fields larger than 0.1$T$. These results indicate that strong quasi-two-dimensional critical fluctuations are present that can be suppressed by magnetic fields. The magnetic and electronic parts of the specific heat $C$${}_M$ show a similar divergence for $0.4\text{K}\le T\le 12$ K, where $C_M/T\sim T^{-0.47\pm 0.03}$. The divergences in ${\chi }^{\prime }$ and $C_M/T$ indicate that YFe${}_2$Al${}_{10}$ is located near a quantum critical point, and no magnetic order is observed above 0.09 K. We argue that our results are inconsistent with quantum impurity or disorder models, suggesting instead that YFe${}_2$Al${}_{10}$ is on the verge of bulk magnetic ordering, and that the critical fluctuations that are associated with this quantum critical point lead to the divergencies in $C_M/T$ and ${\chi }^{\prime }$.

• Received 19 August 2011

DOI:https://doi.org/10.1103/PhysRevB.84.094425