Antiferromagnetic order: type

KCuFj is a ID antiferromagnet (A type) with the spins lying in the ab plane. The magnetic behaviour is again a consequence of antiferrodistortive ordering of distorted octahedra. Interaction between two half-filled orbitals occurs along the c axis... 

Fig. 50. Type-CE antiferromagnetic order in a-b planes antiferromagnetic coupling above c-axis in space group Pbnm (a) ordering of localized occupied e orbitals after Goodenough (1955), and (b) ordering of Zener polarons.

The neodymium based plumbides NdCuPb, NdAgPb, and NdAuPb (Oner et al., 1999) show antiferromagnetic ordering at Tn = 14.6,12.6, and 18.9 K, respectively. These samples revealed an additional transition to a superconducting state at transition temperatures of 7.25, 7.00, and 6.85 K, respectively. The nature of these transitions is still not clear. Due to hystereses behavior of the magnetization of NdAgPb at 5 K, the authors claimed that NdAgPb is a type II superconductor. 

At further increase of x, the long-range antiferromagnetic order is lost and a Kondo-type of behaviour is found in the resistivity curves of compounds withx > 0.10. 

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