Crystallographic, magnetic, thermal, and electric transport properties in UPtIn single crystal

We have studied the crystallographic, magnetic, thermal, and electric transport properties in UPtIn, one of the UTX (T = transition metal, X = Al, Ga, In) families with the hexagonal ZrNiAl structure. A single crystal of UPtIn was prepared by the flux method for the first time. Crystallographic parameters are determined. UPtIn has strong Ising character, the magnetic easy axis being the c-axis. These results determined magnetic properties are consistent with the magnetic structure obtained by neutron scattering measurements. The residual resistivity of our single crystal is 27.9 µΩ cm which is one-third times smaller than that of polycrystalline sample. Specific heat (C) measurements show that the phase transition at 10.5 K, although the antiferromagnetic order takes place at 22 K prepared by arc melt and at 15 K prepared by solid reaction, indicating that the physical properties of UPtIn are dependent on the sample preparation. C=T deviates from T-linear behavior below 1.4 K, indicating that the electronic specific heat coefficient γ is much smaller than that of previous study. The resistivity is almost independent to the temperature below 3.7 K and A coefficient of the quadratic temperature dependence of electrical resistivity is small, indicating that the mass enhancement is small. These results indicate that UPtIn is not a heavy-fermion system.