Eu doping-induced enhancement of magnetocaloric effect in manganite La1.4Ca1.6Mn2O7

• La1.3Eu0.1Sr0.05Ca1.55Mn2O7 shows stronger magnetization than La1.4Ca1.6Mn2O7.
• La1.3Eu0.1Sr0.05Ca1.55Mn2O7 is determined to exhibit a characteristic of first-order phase transition.
• Large magnetocaloric effect as well as scarcely any hysteresis loss is obtained in La1.3Eu0.1Sr0.05Ca1.55Mn2O7.

The structure, magnetic properties and magnetocaloric effects of perovskite manganese oxides La1.4Ca1.6Mn2O7 and La1.3Eu0.1Sr0.05Ca1.55Mn2O7 have been investigated. They undergo a first-order ferromagnetic–paramagnetic phase transition around their respective Curie temperatures (235 K and 215 K, respectively). The doping of Eu and Sr atoms enhances greatly the value of magnetization, which leads to the large magnetocaloric effect. For a field change of 0–5 T, the maximum value of magnetic entropy change is only 4.5 J/kg K for La1.4Ca1.6Mn2O7 compound. However, it increases to 7.1 J/kg K for La1.3Eu0.1Sr0.05Ca1.55Mn2O7 compound. Meanwhile, a large refrigerant capacity of 240.4 J/kg is also achieved. Large reversible magnetocaloric effect and refrigerant capacity indicate the potentiality of La1.3Eu0.1Sr0.05Ca1.55Mn2O7 compound as a candidate for magnetic refrigerant.