The structural,magnetic and magnetocaloric properties of perovskite manganites La_(0.67)Sr_(0.28)Pr_(0.05)Mn_(1-x)Co_(x)O_(3)(x=0.05,0.075 and 0.10)(LSPMCO)are investigated.LSPMCO crystallizes as a rhombohedral struct...The structural,magnetic and magnetocaloric properties of perovskite manganites La_(0.67)Sr_(0.28)Pr_(0.05)Mn_(1-x)Co_(x)O_(3)(x=0.05,0.075 and 0.10)(LSPMCO)are investigated.LSPMCO crystallizes as a rhombohedral structure with R-3c space group.As the Co content increases,the cell volume expands,the Mn-O-Mn bond angle reduces and the length of the MnO bond increases.The samples show irregular submicron particles under a Zeiss scanning electron microscopy.The particle size becomes larger with increasing doping.The chemical composition of the samples is confirmed by x-ray photoelectron spectroscopy(XPS).The ferromagnetic(FM)to paramagnetic(PM)phase transition occurs near the Curie temperature(TC),and all transitions are second-order phase transitions(SMOPT)characterized by minimal thermal and magnetic hystereses.Critical behavior analysis indicates that the critical parameters of LSPMCO closely align with those predicted by the meanfield model.The T_(C)declines with C_(o) doping and reaches near room temperature(302 K)at x=0.075.The maximum magnetic entropy change(-ΔS_(M)^(max))at x=0.05 is 4.27 J/kg·K,and the relative cooling power(RCP)peaks at 310.81 J/K.Therefore,the system holds significant potential for development as a magnetic refrigeration material,meriting further professional and objective evaluation.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.52162038)。
文摘The structural,magnetic and magnetocaloric properties of perovskite manganites La_(0.67)Sr_(0.28)Pr_(0.05)Mn_(1-x)Co_(x)O_(3)(x=0.05,0.075 and 0.10)(LSPMCO)are investigated.LSPMCO crystallizes as a rhombohedral structure with R-3c space group.As the Co content increases,the cell volume expands,the Mn-O-Mn bond angle reduces and the length of the MnO bond increases.The samples show irregular submicron particles under a Zeiss scanning electron microscopy.The particle size becomes larger with increasing doping.The chemical composition of the samples is confirmed by x-ray photoelectron spectroscopy(XPS).The ferromagnetic(FM)to paramagnetic(PM)phase transition occurs near the Curie temperature(TC),and all transitions are second-order phase transitions(SMOPT)characterized by minimal thermal and magnetic hystereses.Critical behavior analysis indicates that the critical parameters of LSPMCO closely align with those predicted by the meanfield model.The T_(C)declines with C_(o) doping and reaches near room temperature(302 K)at x=0.075.The maximum magnetic entropy change(-ΔS_(M)^(max))at x=0.05 is 4.27 J/kg·K,and the relative cooling power(RCP)peaks at 310.81 J/K.Therefore,the system holds significant potential for development as a magnetic refrigeration material,meriting further professional and objective evaluation.
