Ising and Heisenberg models on ferrimagneticAB2chains

We study the Ising and Heisenberg models on one-dimensional ferrimagnetic bipartite chains with the special AB 2 unit-cell topology and experimental motivation in inorganic and organic magnetic polymers. The spin-1/2 AB 2 Ising case is exactly solved in the presence of an external magnetic field. We also derive asymptotical low- and high-temperature limits of several thermodynamical quantities of the zero-field classical AB 2 Heisenberg model. Further, the quantum spin-1/2 AB 2 Heisenberg model in a field is studied using a mean-field approach.