Study of Solid-State Synthesized Pr0.55Sr0.45Mn1-xCrxO3 Perovskites with x=0.0, 0.05, 0.1 and 0.15: Rietveld analysis, Magnetic and Magnetocaloric Properties for Magnetic Refrigeration Applications

Abstract In the current study, the structural (X-ray diffraction XRD), magnetic, critical behavior and magnetocaloric properties of the polycrystalline Pr 0. 55 Sr 0. 45 Mn 1−x Cr x O 3 Manganites with (x = 0. 0, 0. 05, 0. 1 and 0. 15) samples were examined. All our samples have been elaborated by means of the solid-state reaction from stoichiometric powder mixtures of binary oxides at high temperatures. The compounds crystallize in the orthorhombic structure with Pnma space group, according to Rietveld refinement of the XRD pattern. All of the samples exhibit a second-order FM to PM phase transition, according to temperature and field-dependent magnetization measurements; however, the Curie temperature T C value decreases from 300 K to 275 K as the Cr (% x) content increases from 0. 00 to 0. 15. Using Maxwell thermodynamic relations, the magnetocaloric effect MCE in terms of maximum entropy change \ (\: -\: S₌^max\), and relative cooling power RCP has been calculated using isothermal magnetization data around T C. In a magnetic field shift of 5 T, the highest values of the magnetic entropy change \ (\: -\: S₌^max\) have been determined to be 3. 8 J/kg. K, 3. 63 J/kg. K, 3. 87 J/kg. K, and 2. 55 J/kg. K for x = 0. 0, x = 0. 05, x = 0. 1, and x = 0. 15, respectively. For x = 0. 0, x = 0. 05, x = 0. 1, and x = 0. 15 at 5 T, the highest value of the relative cooling power RCP is found to be 247 J/kg, 254. 1 J/kg, 205. 1 J/kg, and 201 J/kg, respectively. The RCP value of 254. 1 J/kg (5% of chromium) is equivalent to 58% of the RCP value of gadolinium metal. Technically, the developed material is highly promising for magnetic refrigeration because of these significant values.