Specific heat and Hall effect of the ferromagnetic Kondo lattice UCu 0.9 Sb 2 .

We have investigated the electrical resistivity ρ, specific heat C p and Hall coefficient R H on a single crystal of a ferromagnetic Kondo lattice UCu0.9 Sb2 . The experimental [Formula: see text], C p (T) and [Formula: see text] data evidence a bulk magnetic phase transition at [Formula: see text] K, and additionally exhibit an unexpected bump located in the temperature range T C /10-T C /3. UCu0.9 Sb2 has an enhanced electronic specific heat coefficient [Formula: see text] mJ molK-2 , corresponding to Kondo temperature [Formula: see text] K. An analysis of the Hall effect data for j//(a, b)-plane and H// c-axis reveals that the low-temperature ordinary Hall coefficient R 0 is positive, suggesting that p-type electrical conductivity is dominant. The density of the carriers at 2 K is about 0.6 holes f.u.-1 , which may categorize the studied compound into class of low carrier density compounds. Combined γ and R 0 data divulge an effective mass of charge carriers [Formula: see text] 27 m e . This finding together with quite low Hall mobility [Formula: see text] cm2 Vs-1 and Kadowaki-Woods ratio [Formula: see text] [Formula: see text] cm (mol K2 mJ-1 )2 , manifest the development of heavy-fermion state in the ferromagnetic UCu0.9 Sb2 compound at low temperatures.