  Effect of the trimodal random magnetic field distribution on the phase
diagrams of the anisotropic quantum Heisenberg model has been investigated for
three dimensional lattices with effective field theory (EFT) for a two spin
cluster. Variation of the phase diagrams with the random magnetic field
distribution parameters has been obtained and the effect of the anisotropy in
the exchange interaction on the phase diagrams has been investigated in detail.
Particular attention has been devoted on the behavior of the tricritical points
with random magnetic field distribution.
