Analysis based on scaling relations of critical behaviour at PM–FM phase transition and universal curve of magnetocaloric effect in selected Ag-doped manganites

摘要: The critical behaviour of Pr0.5Sr0.5−xAgxMnO3 (0 ≤ x 0.2) samples around the paramagnetic–ferromagnetic phase transition is studied based on isothermal magnetization measurements. assessments Banerjee's criteria reveal undergoing a second-order magnetic transition. Various techniques such as modified Arrott plot, Kouvel–Fisher method, and isotherm analysis were used to determine values ferromagnetic temperature TC, well exponents β, γ δ. exponents, derived from data using are found be (β = 0.43 ± 0.002, 0.363 0.068 0.328 0.012), (γ 1.296 0.007, 1.33 0.0054 1.236 0.012) for 0.0, 0.1 0.2, respectively. This implies that with 0 0.2 systems does not belong single universality class indicates presence disorder in system must taken into account fully describe microscopic interaction these manganites. With values, magnetic-field dependences at temperatures TC can described following equation state our samples. From entropy change (ΔSM), it was possible evaluate transitions. Their good agreement those obtained plot (MAP). We scaling hypotheses scale heat capacity changes universal curve respectively