From specific heat to cooling power: a calorimetric evaluation of Pr0.6Sr0.4-xKxMnO₃ manganites.

The potassium-doped ceramics Pr0.6Sr0.4xKxMnO₃ (withx= 0.05 andx= 0.1) were investigated through comprehensive heat capacity measurements to evaluate their magnetocaloric properties under magnetic fields up to 2 T across a broad temperature range. Complementary magnetization analyses were also conducted to support the findings. Heat capacity data revealed a paramagnetic-to-ferromagnetic (PM-FM) phase transition occurring at 298 K forx= 0.05 and at 292 K forx= 0.1. Application of a magnetic field resulted in a shift of the transition temperature toward higher values in both compositions. Indirect estimations of the magnetic entropy change (ΔSM) and adiabatic temperature change (ΔTAD) at the maximum applied field yielded values of 2.29 J (kg· K)-1and 1.22 K forx= 0.05, and 2.64 J (kg· K)-1and 1.30 K forx= 0.1, respectively-highlighting the magnetocaloric potential of these materials. These entropy change values were further compared with those derived from magnetization measurements, showing good consistency. Additionally, the relative cooling power (RCP) was estimated and benchmarked against representative manganite systems. The obtained RCP values were 50 J kg-1forx= 0.05 and 66 J kg-1 forx= 0.1 under a 2 T field, aligning well with values reported for similar compounds. The dependence of both ΔSMand ΔTADon the magnetic field followed a power-law behavior, in fair agreement with existing literature, reinforcing the reliability of the observed magnetocaloric effects.