Magnetic transitions and quantum spin fluctuation of (Gd1.85Ce0.15)CuO4-δ

[[abstract]]Magnetic and calorimetric measurements have been carried out on the insulating compound (Gd1.85Ce0.15)CuO4-δ. As the only nonsuperconducting member of the (R1.85Ce0.15)CuO4-δ system (R=Pr, Nd, Sm, Eu, Gd), its Cu spins undergo a canted antiferromagnetic ordering at TN(Cu) near 162 K. Spin reorientation occurs at Tsr(Cu) near 14 K to become truly antiferromagnetic. While these transitions were identified by magnetic measurements, no heat capacity anomaly was observed at either TN(Cu) or Tsr(Cu). In contrast, at TN(Gd)=5.3 K antiferromagnetic ordering of Gd3+ prevails with the expected entropy change of 1.85Rln8[[fileno]]2010102010051[[department]]物理