Magnetocaloric effect in manganites in alternating magnetic fields

Direct measurements of the magnetocaloric effect in La0.7Ca0.3MnO3, La1_xAgyMnO3, and Sm1_xSrxMnO3 manganites in alternating magnetic fields at frequencies up to 20 Hz and an amplitude of 6.2 kOe are carried out. A decrease of the MCE with the field frequency reaching 20%, 55% and 70% in La0.7Ca0.3MnO3, Sm1_xSrxMnO3 and La1_xAgyMnO3 is discovered in all studied manganites. The value estimates of the cooling power depending on the frequency of the alternating magnetic field are carried out. The largest value among the studied materials is achieved for La0.7Ca0.3MnO3 manganite, which is the most promising to be used in magnetic refrigeration technology. The data are compared with those for Gd in the same conditions.

Automated summary

Direct measurements were conducted on La0.7Ca0.3MnO3, La1_xAgyMnO3, and Sm1_xSrxMnO3 manganites to investigate their magnetocaloric effect in alternating magnetic fields. The results showed a decrease in the magnetocaloric effect with increasing field frequency, reaching 20%, 55%, and 70% for La0.7Ca0.3MnO3, Sm1_xSrxMnO3, and La1_xAgyMnO3, respectively. Among the studied materials, La0.7Ca0.3MnO3 exhibited the highest cooling power, making it a promising candidate for magnetic refrigeration technology. A comparison with Gd under the same conditions was conducted.