Heavy fermion compound SmOs₄Sb₁₂ in vicinity of ferromagnetic critical point

We report nuclear quadrupole resonance (NQR) measurement at ambient pressure and resistivity measurement under high pressure in the new heavy fermion (HF) compound SmOs₄Sb₁₂. The NQR spectrum and the nuclear spin-lattice relaxation rate (1/T1) clearly demonstrate the bulk nature of ferromagnetic ordering below T_C ∼ 2 K. The temperature dependence of 1/T1 exhibits the characteristic behaviors of a Kondo lattice. The application of pressure decreases Kondo temperature and stabilizes the magnetic ordering, which is the same tendency as that found in some Yb-based compounds. The obtained phase diagram indicates SmOs₄Sb₁₂ to be in the vicinity of its ferromagnetic critical point.