Fig. 1: Barocaloric effects of NH4I.
From: Ultrasensitive barocaloric material for room-temperature solid-state refrigeration
a Phase diagram of NH4I as functions of temperature and pressure. The cooling (down-triangle) and heating transition (up-triangle) temperatures are derived from calorimetric data in Supplementary Fig. 2a. b Pressure-induced isothermal entropy change, \(\Delta {S}_{{P}_{0}\to P}\), for the cooling and heating processes. c Much larger pressure-dependent transition temperature variation \(\left|{{{{{\rm{d}}}}}}{T}_{{{{{{\rm{t}}}}}}}/{{{{{\rm{d}}}}}}P\right|\) and smaller saturation driving pressure compared with other giant barocaloric materials8,17,18,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39. d High barocaloric strength as estimated through \(\left|\Delta {S}_{{P}_{0}\to P}^{{{\max }}}/\triangle P\right|\)34. The data for the samples marked by ‘*’ represents the reversible values with the influence of thermal hysteresis excluded. Details are summarized in Supplementary Table 1.
