Large magnetocaloric effect and critical behavior in Sm0.09Ca0.91MnO3 electron-doped nanomanganite

Abstract

The magnetic properties and magnetocaloric effect (MCE) in electron-doped Sm0.09Ca0.91MnO3 nanomanganite have been investigated in detail by magnetization and heat capacity measurements. The maximum magnetic entropy change and the relative cooling power (RCP) are found to be, respectively, and for a 7 T magnetic field change along with a negligible hysteresis loss, making of this material a promising candidate for magnetic refrigeration at low temperature. The maximum value of occurs close to the Curie temperature . The values of and RCP are comparable to a few hole-doped manganite. To investigate the nature of the paramagnetic-to-ferromagnetic phase transition, critical exponent study has been carried out. Based on the modified Arrott plot, we have determined the values of critical parameters ( and δ) and conclusively shown that Sm0.09Ca0.91MnO3 has nearly mean-field–like long-range interaction. The calculated values of critical exponents not only obey the scaling hypothesis, but also corroborate the results obtained employing the Kouvel-Fisher method. The re-scaled magnetic entropy change curves for different applied magnetic fields collapse into a single master curve for this electron-doped manganite indicating clearly a second-order magnetic phase transition. Such noticeably large at low magnetic field makes this material a potential candidate for low-temperature magnetic refrigeration.