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The magnetic and magnetocaloric properties were studied in orthorhombic polycrystalline GdScO 3. GdScO 3 possesses an antiferromagnetic ordering below the Néel temperature ∼2.8 K. Negligible thermal and magnetic hystereses were both observed in GdScO 3 , indicating a second-order feature of phase transition and a reversible magnetocaloric effect (MCE). In the magnetic field changes of 0–50 kOe and 0–70 kOe, giant maximum magnetic entropy changes of 39.39 J/kg K and 50.77 J/kg K were obtained near the liquid helium temperature, respectively. The giant reversible MCE indicates the polycrystalline GdScO 3 is a very promising refrigerant candidate for the low-temperature magnetic refrigeration. [ABSTRACT FROM AUTHOR]

The magnetic properties and magnetocaloric effect (MCE) of binary intermetallic compound Er 3 Pd 2 were studied. It exhibits a paramagnetic (PM) to antiferromagnetic (AFM) transition at Néel temperature (T N ) = 10 K. A large reversible MCE was observed which is related to a second order magnetic transition from PM to AFM state. The values of maximum magnetic entropy change ( - Δ S M max ) and adiabatic temperature change ( Δ T ad max ) reach 8.9 J/kg-K and 2.9 K respectively for the field change of 50 kOe with no obvious hysteresis loss. The effective magnetic moment was determined to be 10.16 µ B /Er 3+ , which is notably higher than that of free ion value of Er 3+ (9.59 µ B ), suggests that Pd ions also have considerable amount of magnetic moments in this compound. [ABSTRACT FROM AUTHOR]

Magnetic materials with reversible magnetocaloric effect across their respective first-order magneto-structural transitions (MST) have vital significance for further advancement towards the ultimate goal of practical magnetic cooling applications. In this present study, the reversibility of the MST is investigated by analyzing the isofield curves under different minor and major thermal hysteresis loops and the isothermal curves under different magnetic field cycles. The reversibility of the magnetocaloric effect (MCE) depends upon the width of the nucleation energy barrier existing across the MST. Minor hysteresis loops are found to be minimizing the energy loss by preventing the nucleation of the martensite phase and can be easily returned to the austenite phase immediately while switching from cooling to heating. A large reversible isothermal magnetic entropy change Δ S M of −14.4 J kg−1 K−1 nearly at 322 K is observed for the (Mn 0.45 Fe 0.55) (Ni 0.6 Co 0.4) Si alloy under a low magnetic field change of 3 T. The observed large reversible MCE, very low magnetic field-induced hysteresis loss, and large reversible RC effe ∼ 155 J kg−1 will be beneficial for reducing the energy loss during several magnetic field cycles in practical cooling applications which makes this alloy promising for the development of efficient magnetic refrigerants. • Largest reversible Δ S M ∼ -14.4 Jkg−1K−1 is observed in Mn-Ni-Si based alloys for Δ H ∼ 3 T. • Minor hysteresis loops minimize the negative impact of thermal hysteresis on MCE. • Overlapping nature of successive M-H cycles confirm the reversibility of MCE. • Large sensitivity (2.75 KT−1) of MST helps to obtain a large Δ S tr ∼ 38.2 Jkg−1K−1. [ABSTRACT FROM AUTHOR]

Abstract: Magnetocaloric effect of MnV1.95Al0.05O4 was studied by the magnetization and heat capacity measurements. MnV1.95Al0.05O4 is a cubic spinel structure with ferromagnetism of second order in nature and performs reversible magnetic entropy around the magnetic transition temperature. The large magnetic entropy changes −ΔS M ∼5.2 and 8.2J/kgK and the adiabatic temperature changes ΔT ad ∼1.5 and 2.6K are revealed for the magnetic field changes of 2 and 4T near the Curie temperature (T C ) of 59.6K, respectively. The relative cooling power (RCP) are about 82.2 and 177.2J/kg K for magnetic field changes 2 and 4T, respectively. Compared with the parent compound, although the −ΔS M and ΔT ad become smaller, the refrigeration working temperature span and the RCP have been improved. [Copyright &y& Elsevier]