The role of finite size effects on magnetic order has been investigated in samarium nanoparticles prepared by physical vapor deposition. A dense layer composed of distinct nanoparticles with a mean particle diameter of 26 nm was deposited on a diamagnetic substrate. M(T) measurements identify the expected pair of antiferromagnetic ordering temperatures in the bulk Sm precursor, at 113 K and 14 K, where the magnetic unit cell for the lower ordering temperature is 10.36 nm along the c-axis. The high temperature ordering of the hexagonal sites in the Sm nanocrystals is slightly decreased with respect to that of bulk Sm, while the low temperature transition associated with the cubic sites is significantly suppressed. The observed changes are attributed to finite size effects, with ordering suppressed as the particle radius approaches the length of the magnetic unit cell, and surface moments become more prominent.

中文翻译：

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抑制钐纳米粒子中的低温磁有序

在通过物理气相沉积制备的钐纳米粒子中研究了有限尺寸效应对磁序的作用。由平均粒径为 26 nm 的不同纳米颗粒组成的致密层沉积在抗磁性基材上。M(T) 测量确定了块状 Sm 前驱体中预期的一对反铁磁排序温度，分别为 113 K 和 14 K，其中较低排序温度的磁性晶胞沿 c 轴为 10.36 nm。Sm 纳米晶体中六边形位点的高温排序相对于块状 Sm 略有降低，而与立方位点相关的低温转变受到显着抑制。观察到的变化归因于有限尺寸效应，