Thermodynamics and critical behaviors of topological dS black holes with nonlinear source

We discuss black hole solutions of Einstein gravity in presence of nonlinear electrodynamics in dS spacetime. Considering prescribed entropy, thermodynamic volume of dS spacetime, We investigate properties of the effective thermodynamic quantities under influence of nonlinearity parameter $\alpha$. They show a similar phase transition and criticality properties with that of black holes in AdS spacetime. And the nonlinearity parameter $\alpha$ combined with electric charge is found to have effects on the phase structure. By the Ehrenfest equations we prove the critical phase transition is a second order equilibrium transition.