Magnetic properties of exactly solvable doubly decorated Ising-Heisenberg planar models

Applying the decoration-iteration procedure, we introduce a class of exactly solvable doubly decorated planar models consisting both of the Ising- and Heisenberg-type atoms. Exact solutions for the ground state, phase diagrams, and basic physical quantities are derived and discussed. The detailed analysis of the relevant quantities suggests the existence of an interesting quantum antiferromagnetic phase in the system.