Integer spin-chain antiferromagnetism of the 4d oxide CaRuO3 with   post-perovskite structure
  A quasi-one dimensional magnetism was discovered in the post-perovskite CaRuO3 (Ru4+: 4d4, Cmcm), which is iso-compositional with the perovskite CaRuO3 (Pbnm). An antiferromagnetic spin-chain function with -J/kB = 350 K well reproduces the experimental curve of the magnetic susceptibility vs. temperature, suggesting long-range antiferromagnetic correlations. The anisotropic magnetism is probably owing to the dyz - 2p- dzx and dzx - 2p- dyz superexchange bonds along a-axis. The Sommerfeld coefficient of the specific heat is fairly small, 0.16(2) mJ mol-1 K-2, indicating that the magnetism reflects localized nature of the 4d electrons. As far as we know, this is the first observation of an integer (S = 1) spin-chain antiferromagnetism in the 4d electron system. 
Y. Shirako (Gakushuin U), H. Satsukawa (GU), X. X. Wang (NIMS), J. J.   Li (NIMS), Y. F. Guo (NIMS), M. Arai (NIMS), K. Yama...
cond-mat.str-el cond-mat.supr-con