Single crystal of PrSi was grown by Czochralski method in a tetra-arc furnace. Powder x-ray diffraction of the as grown crystal revealed that PrSi crystallizes in FeB$-$type structure with space group $Pnma$ (no. 62). PrSi undergoes a ferromagnetic transition at 52 K with [010] direction as the easy axis of magnetization. Heat capacity data confirm the bulk nature of the transition at 52 K and exhibit a huge anomaly at the transition. A sharp rise in the low temperature heat capacity has been observed (below 5 K) which is attributed to the $^{141}$Pr nuclear Schottky heat capacity arising from the hyperfine field of the Pr moment. The estimated Pr magnetic moment 2.88 $μ_{\rm B}$/Pr from the hyperfine splitting is in agreement with the saturation magnetization value obtained from the magnetization data measured at 2 K. From the crystal electric field (CEF) analysis of the magnetic susceptibility, magnetization and the heat capacity data it is found that the degenerate $J = 4$ Hund's rule derived state of Pr$^{3+}$-ion splits into nine singlets with an overall splitting of 284 K, the first excited singlet state separated by just 9 K from the ground state. The magnetic ordering in PrGe appears to be due to the exchange generated admixture of low lying crystal field levels. Magnetocaloric effect (MCE) has been investigated from magnetization data along all the three principal crystallographic directions. Large magnetic entropy change, $-ΔS_M = $22.2 J/kg K, and the relative cooling power, RCP = $460$ J/kg, characteristic of giant magneto caloric effect are achieved near the transition temperature ($T_{\rm C}$ = 52 K) for $H =$~70 kOe along $[010]$. Furthermore, the PrSi single crystal exhibits a giant MCE anisotropy.
Giant magnetocaloric effect in magnetically frustrated EuHo$_2$O$_4$ and EuDy$_2$O$_4$ compounds
通过磁化强度和热容量的测量，研究了EuHo $_2$ O $_4$和EuDy $_2$ O $_4$的磁性和磁热性质。这些化合物经历了场诱导的反铁磁到铁磁的转变，并表现出巨大的熵变。对于0-8 T的场变化，最大磁熵和绝热温变分别为30（25）J kg $^{-1}$ K $^{-1}$和12.7（16）K，对应的制冷剂容量值为540（415）J kg $^{-1}$，用于EuHo $_2$ MM O PDMATHAMN（EuDy $_2$ O $_4$）。这些磁热参数也保持大到最低温度测量，甚至大于一些潜在的磁制冷剂在相同的温度范围内报告的一个温和的磁场变化。此外，这些材料是高度绝缘的，并且没有表现出热和场滞后，满足了在低温区域中良好的磁制冷剂的必要条件。
3d-4f spin interaction induced giant magnetocaloric effect in zircon-type DyCrO4 and HoCrO4 compounds
通过磁化强度和热容测量研究了3d-4f自旋相互作用对DyCrO $_4$和HoCrO $_4$化合物磁性和磁热性质的影响。由于铁磁和反铁磁超交换相互作用的强烈竞争，这两种化合物在铁磁转变前后都表现出复杂的磁性和巨大的磁熵变。当磁场变化为8 T时，磁熵变的最大值（$ΔS_{M}^{max}$），绝热温度变化（$ΔT_{ad}$）和制冷剂容量（RC）对于DyCrO $_4$分别达到29 J kg $^{-1}$ K $^{-1}$、8 K和583 J kg $^{-1}$，而对于HoCrO $_4$的相应值分别为31 J kg $^{-1}$ K $^{-1}$、12 K，和622 J kg $^{-1}$。对于中等场变化，$ΔS_{M}^{max}$、$ΔT_{ad}$和RC也相当大。锆型DyCrO $_4$和HoCrO $_4$具有较大的磁热参数，是一种具有潜力的氢液化磁制冷材料。
Metastable magnetization behavior in magnetocaloric R6Co1.67Si3 (R=Tb and Nd) compounds
在最近发现的三元硅化物R6 Co 1.67Si 3中观察到了磁场和时间诱导的台阶。在低温磁化等温线的不同环中观察到巨大的弛豫台阶。该系统中存在的巨弛豫现象表明，在一定的磁场下，存在一个达到饱和时刻的孕育时间。在该系统中观察到的测量协议敏感的磁化行为可能是由强磁结构耦合和/或磁阻挫引起的。电阻率和磁阻也反映了化合物的磁性状态。磁热效应被发现是大的温度接近磁转变温度。
Frustration induced inversion of magnetocaloric effect and enhanced cooling power in substituted Pyrochlore Iridates
我们研究了局部3d Cr 3+磁矩部分取代5d Ir 4+位置对Y2 Ir 2 O 7（YIO）烧绿石铱酸盐磁热性能的影响。我们发现，Y2 Ir 2-xCrxO 7（YICO）发生团簇玻璃化转变，可能是由于RKKY一样的本地化的Cr 3+时刻占据烧绿石网络中的随机站点之间的相互作用，介导的5d Ir传导电子。铁磁团簇和反铁磁团簇的共存导致了常规磁热效应和逆磁热效应。我们观察到显着增强传统以及逆MCE与替代。虽然传统的MCE和反MCE在取代的铱酸盐的值不大，效果跨越一个巨大的工作温度窗口，从而导致数量级的增强冷却功率，该值是可比的标准磁热材料。
Mixed magnetism, nanoscale electronic segregation and ubiquitous first order transitions in giant magnetocaloric MnFeSiP alloys detected by $^{55}$Mn NMR
Giant magnetocaloric effect at low fields in triangular-lattice NdMgAl$_{11}$O$_{19}$
Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）；Songshan Lake Materials Laboratory（松山湖材料实验室）；University of Chinese Academy of Sciences（中国科学院大学）；Huazhong University of Science and Technology（华中科技大学）；Great Bay University（大湾区大学）
Exact eigenstates of highly frustrated spin lattices probed in high fields
强阻挫反铁磁体如磁性分子{Mo 72 Fe 30}、kagome或烧绿石晶格表现出各种迷人的性质，如低位单线态、磁化平台以及磁化跳变。在最近几年中，精确的多体本征态可以为这些自旋系统中的几个构建。这些态在高磁场中成为基态，并且它们也导致奇异行为。理解这些性质的一个关键概念是由独立的定域磁振子提供的。这些n-磁振子态的能量本征值与独立磁振子的数目n成线性比例，因此与总磁量子数M=Ns-n成线性比例。在外加磁场中，这导致了一个巨大的磁化跳变，构成了一个新的宏观量子效应。它将被证明，这种行为是伴随着一个大规模的简并，广泛的（T=0）熵，从而在饱和磁场的大磁热效应。将概述与平带铁磁性的联系。
