Strong spin fluctuations and possible non-Fermi-liquid behavior in AlCNi3

We have synthesized the antiperovskite compound AlCNi3 and performed a detailed study of its basic properties. The magnetic properties show that AlCNi3 is a strongly exchange-enhanced Pauli paramagnet in the very vicinity of ferromagnetic order. The low-temperature electronic specific heat reveals that the spin fluctuations in AlCNi3 are strongly enhanced when compared with the superconducting MgCNi3, while the electron-phonon couplings are comparable in both compounds. The resistivity rho(T)proportional to T (2 similar to 70 K) indicates a possible non-Fermi-liquid behavior, which is suggested to correspond to the strong spin fluctuations. The Wilson ratio (similar to 2.4) and the dimensionless ratio that connects the low-temperature Seebeck coefficient with the Sommerfeld specific heat constant indicate that AlCNi3 can be considered as a modest electron-correlated material. The study of the Seebeck coefficient also suggests the complexity of the electronic structure in AlCNi3, e.g., a highly distorted Fermi surface, which may be associated with its particular properties.