  We study the properties of nonequilibrium systems modelled as spin models
without defined Hamiltonian as the majority voter model. This model has
transition probabilities that do not satisfy the condition of detailed balance.
The lack of detailed balance leads to entropy production phenomena, which are a
hallmark of the irreversibility. By considering that voters can diffuse on the
lattice we analyze how the entropy production and how the critical properties
are affected by this diffusion. We also explore two important aspects of the
diffusion effects on the majority voter model by studying entropy production
and entropy flux via time-dependent and steady state simulations. This study is
completed by calculating some critical exponents as function of the diffusion
probability.
