Heavy Fermion Compound SmOs₄Sb₁₂ in Vicinity of Ferromagnetic Critical Point

Abstract

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.