The relationship between isothermal magnetic entropy change DELTA S andadiabatic temperature change DELTA T_(ad) was deduced according to the principles of thermodynamics.The MCE and the engineering application were d...The relationship between isothermal magnetic entropy change DELTA S andadiabatic temperature change DELTA T_(ad) was deduced according to the principles of thermodynamics.The MCE and the engineering application were discussed for Gd and several new kinds of magneticrefrigerating materials near room temperature, Gd_5Si_2Ge_2, MnFeP_(0.45)As_(0.55) and LaFe_(11.2)Co_(0.7)Si_(1.1). Isothermal entropy change is proportional to adiabatic temperature change with afactor of T/C (T is temperature, C is heat capacity). When the comparison of magnetacoloric effectis made for two different materials, we should consider isothermal entropy change as well asadiabatic temperature change.展开更多
Magnetic properties and magnetocaloric effects （MCEs） of the PrSi compound were studied. The PrSi compound undergoes a second-order ferromagnetic-to-paramagnetic transition at the Curie temperature of Tc = 52 K. Lar...Magnetic properties and magnetocaloric effects （MCEs） of the PrSi compound were studied. The PrSi compound undergoes a second-order ferromagnetic-to-paramagnetic transition at the Curie temperature of Tc = 52 K. Large MCE with no magnetic hysteresis loss is observed around Tc. The maximum values of magnetic entropy change （△S） are found to be -8.6 and -15.3 J.kg^-1.K^-1 for the magnetic field changes of 0-2 T and 0-5 T, respectively. The large △S with no hysteresis makes PrSi compound a competitive candidate for magnetic refrigerant.展开更多
文摘The relationship between isothermal magnetic entropy change DELTA S andadiabatic temperature change DELTA T_(ad) was deduced according to the principles of thermodynamics.The MCE and the engineering application were discussed for Gd and several new kinds of magneticrefrigerating materials near room temperature, Gd_5Si_2Ge_2, MnFeP_(0.45)As_(0.55) and LaFe_(11.2)Co_(0.7)Si_(1.1). Isothermal entropy change is proportional to adiabatic temperature change with afactor of T/C (T is temperature, C is heat capacity). When the comparison of magnetacoloric effectis made for two different materials, we should consider isothermal entropy change as well asadiabatic temperature change.
基金financially supported by the National Natural Science Foundation of China(No.11274357)the Hi-Tech Research and Development Program of China(No.2011AA03A404)
文摘Magnetic properties and magnetocaloric effects （MCEs） of the PrSi compound were studied. The PrSi compound undergoes a second-order ferromagnetic-to-paramagnetic transition at the Curie temperature of Tc = 52 K. Large MCE with no magnetic hysteresis loss is observed around Tc. The maximum values of magnetic entropy change （△S） are found to be -8.6 and -15.3 J.kg^-1.K^-1 for the magnetic field changes of 0-2 T and 0-5 T, respectively. The large △S with no hysteresis makes PrSi compound a competitive candidate for magnetic refrigerant.
