Successive magnetic transitions in the heavy-fermion superconductor Ce3 PtIn11 studied by 115In nuclear quadrupole resonance

Nuclear quadrupole resonance (NQR) measurements were performed on the heavy-fermion superconductor Ce3 PtIn11 with Tc = 0.32 K. The temperature dependence of both spin-lattice relaxation rate 1 / T1 and NQR spectra evidences the occurrence of two successive magnetic transitions with TN1 ≃ 2.2 K and TN2 ≃ 2.0 K . In successive magnetic transitions, even though the magnetic moment at the Ce(2) site plays a major role, the magnetic moment at the Ce(1) site also contributes to some extent. While a commensurate antiferromagnetic ordered state appears for TN2 < T < TN1, a partially incommensurate antiferromagnetic ordered state is suggested for T < TN2.