A setup for direct measurement of the adiabatic temperature change in magnetocaloric materials

Abstract

In order to find a highly efficient, environment-friendly magnetic refrigerant, direct measurements of the adiabatic temperature change $\Delta T_{adb}$ is required. Here, in this work, a simple setup for the $\Delta T_{adb}$ measurement is presented. Using a permanent magnet Halbach array with a maximum magnetic field of $1.8$ T and a rate of magnetic field change of $5$ T/s, accurate determination of $\Delta T_{adb}$ is possible in this system. The operating temperature range of the system is from $100$ K to $400$ K, designed for the characterization of materials with potential for room temperature magnetic refrigeration applications. Using the setup, the $\Delta T_{adb}$ of a first-order and a second-order compound have been studied. Results from the direct measurement for the first-order compound have been compared with $\Delta T_{adb}$ calculated from the temperature and magnetic field dependent specific heat data. By comparing results from direct and indirect measurements, it is concluded that for a reliable characterization of the magnetocaloric effect, direct measurement of $\Delta T_{adb}$ should be adopted.

References in corpus (4)

• Cooling and heating by adiabatic magnetization in the Ni${}_{50}$Mn${}_{34}$In${}_{16}$ magnetic shape memory alloy
• High-throughput direct measurement of magnetocaloric effect based on lock-in thermography technique
• Effect of small cation occupancy and anomalous Griffiths phase disorder in nonstoichiometric magnetic perovskites
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Cited by in corpus (3)

• Giant magnetocaloric effect in the (Mn,Fe)NiSi-system
• Design of thermal hysteresis in nonstoichiometric alloys with giant magnetocaloric effect
• Insight into magnetocaloric properties of Mn2Nb molecular magnet by relaxation calorimetry: A comprehensive case study