Self-consistent mean-field theory of the XXZ ferrimagnetic spin chain with single-ion anisotropy

The extended self-consistent mean-field theory is applied to study the XXZ ferrimagnetic spin chain with single-ion anisotropy. Based on the effects of XXZ anisotropy λ and single-ion anisotropy D, we calculate the energy excitation spectrums, energy gaps, static uniform susceptibility and specific heat. The magnetization plateau of ferrimagnetic spin chain with single-ion anisotropy D   disappears at the critical point Dc=1.335Dc=1.335.