Gegen Bao, Huhe Bao, Ou Zhi-Qiang, Guillou Francois, Yibole Hargen
College of Physics and Electronic Information, Inner Mongolia Key Laboratory of Applied Condensed Matter Physics, Inner Mongolia Normal University, 81 Zhaowuda Rd, Hohhot 010022, China.
Normandie University, ENSICAEN, UNICAEN, CNRS, CRISMAT, 14000 Caen, France.
Materials (Basel). 2025 Jul 1;18(13):3104. doi: 10.3390/ma18133104.
The NdIn compound exhibits an intriguing borderline first-/second-order transition at its Curie temperature. Several studies have pointed to its potential for magnetic cooling, but also raised controversies about the actual order of the transition, the amplitudes of the hysteresis, and of its magnetocaloric effect. Here, we estimate the thermal hysteresis using magnetic and thermal measurements at different rates. It is found to be particularly small (0.1-0.4 K), leading to almost fully reversible adiabatic temperature changes when comparing zero-field cooling and cyclic protocols. Some open questions remain with regard to the magnetostriction of NdIn, which is presently found to be limited, in line with the absence of a thermal expansion discontinuity at the transition. The comparison of the magnetocaloric effect in NdIn and EuIn highlights that the limited saturation magnetization of the former affects its performance. Further efforts should therefore be made to design materials with such borderline first-/second-order transitions using heavier rare earths.
钕铟化合物在其居里温度下呈现出一种有趣的一级/二级转变临界情况。多项研究指出了其在磁制冷方面的潜力，但也引发了关于转变的实际阶次、磁滞幅度及其磁热效应的争议。在此，我们通过以不同速率进行的磁性和热测量来估算热滞。结果发现热滞特别小（0.1 - 0.4 K），这使得在比较零场冷却和循环过程时，绝热温度变化几乎完全可逆。关于钕铟的磁致伸缩仍存在一些未解决的问题，目前发现其磁致伸缩是有限的，这与转变处不存在热膨胀不连续性一致。钕铟和铕铟磁热效应的比较突出表明，前者有限的饱和磁化强度影响了其性能。因此，应进一步努力使用重稀土来设计具有这种一级/二级转变临界情况的材料。
