Magnetically Charged AdS Black Holes and Joule–Thomson Expansion

The process of the Joule–Thomson adiabatic expansion within rational NED (RNED)-AdS spacetime is investigated. The isenthalpic $$P{-}T$$ diagrams and the inversion temperature are depicted. The inversion temperature depends on the magnetic charge and RNED coupling constant of black holes. When the Joule–Thomson coefficient vanishes, a cooling-heating phase transition occurs. We consider the cosmological constant as a thermodynamic pressure, and the black hole mass is treated as chemical enthalpy.