Magnetization steps of $J_{1}$ quintets in the hcp lattice
The magnetization steps of quintet clusters, consisting of five identical magnetic ions coupled by isotropic nearest neighbors antiferromagnetic exchange interaction in the hcp lattice, have been investigated. In that model, called the $J_1$ model, there are 17 types of quintets. The values of the magnetic field of the magnetization steps of the clusters have been determined by the numerical diagonalization of the spin Hamiltonian. The simulations have been performed for quintets composed of individual spin $S$ = 1/2, 3/2 and 5/2. The contribution of the quintets to the effective concentration (or technical saturation) as a function of the magnetic ion concentration was also calculated.