Joule-Thomson expansion for hairy black holes

We study the Joule-Thomson (JT) expansion of hairy black hole in AdS5 spacetime. We first investigate the inversion temperature and isenthalpic curve in the P−T plane of the system. The isenthalpic curves are divided into two parts by the inversion curve, above which the system undergoes a cooling process while below which it is in heating process during JT expansion. We then investigate the ratio between the minimum inversion temperature and the pressure-volume (PV) critical temperature. It is found that the scalar hair suppresses the ratio, while the electric charge enhances it. This finding indicates that the scalar hair activates the effect of electric charge, because the ratio in the normal charged black hole is a constant, independent of the electric charge. Our study completes the thermodynamic phenomena in the extended thermodynamic of scalar hairy black hole.