论文标题
直接测量绝热温度变化的磁化材料的设置
A setup for direct measurement of the adiabatic temperature change in magnetocaloric materials
论文作者
论文摘要
为了找到高效，环境友好的磁性制冷剂，需要直接测量绝热温度变化$ΔT_{ADB} $。在这里，在这项工作中，提出了$ΔT_{ADB} $测量的简单设置。使用永久磁铁HALBACH阵列，最大磁场为$ 1.8 $ t，磁场更改$ 5 $ t/s，在此系统中可以准确确定$ΔT_{ADB} $。系统的工作温度范围从$ 100 $ K到$ 400 $ K，设计用于表征具有室温磁制冷应用的材料。使用设置，已经研究了一阶和二阶化合物的$ΔT_{ADB} $。将一阶化合物的直接测量结果与从温度和磁场依赖于特定的热数据计算得出的$ΔT_{ADB} $进行了比较。通过比较直接测量和间接测量的结果，可以得出结论，对于对磁平衡效应的可靠表征，应采用$ΔT_{ADB} $的直接测量。
In order to find a highly efficient, environment-friendly magnetic refrigerant, direct measurements of the adiabatic temperature change $ΔT_{adb}$ is required. Here, in this work, a simple setup for the $ΔT_{adb}$ 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 $ΔT_{adb}$ 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 $ΔT_{adb}$ 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 $ΔT_{adb}$ 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 $ΔT_{adb}$ should be adopted.
