Joule-Thomson expansion of charged dilatonic black holes

Based on the Einstein-Maxwell theory, the Joule-Thomson (J-T) expansion of charged dilatonic black holes (the solutions are neither flat nor AdS) in (n + 1)-dimensional spacetime is studied herein. To this end, we analyze the effects of the dimension n and dilaton field alpha on J-T expansion. An explicit expression for theJ-T coefficient is derived, and consequently, a negative heat capacity is found to lead to a cooling process. In contrast to its effect on the dimension, the inversion curve decreases with charge Q at low pressures, whereas the opposite effect is observed at high pressures. We can observe that with an increase in the dimension n or parameter alpha, both the pressure cut-off point and the minimum inversion temperature T(min )change. Moreover, we analyze the ratio T-min/T-c merically and discover that the ratio is independent of charge; however, it depends on the dilaton field and dimension: for n= 3 and alpha= 0 , the ratio is 1/2. The dilaton field is found to enhance the ratio. In addition, we identify the cooling-heating regions by investigating the inversion and isenthalpic curves, and the behavior of the minimum inversion mass M-min indicates that this cooling-heating transition may not occur under certain special conditions.