Thermodynamic Phase Transition and Critical Behavior of a Spherical Symmetric Black Hole

In this paper, we builded the thermodynamics model of black hole based on the method of York. We obtained the reduced temperature reciprocal function using the action of the system. We studied the phase structure of black holes and Hawking-Page phase transition. We obtained the first order phase transition and critical values of black hole in Rerssner-NordstrÖm space time. The results showed that only when two-phase coexistence appeared only when |q| < |q_c|.