Giant isotropic negative thermal expansion in Y-doped samarium monosulfides by intra-atomic charge transfer
Giant isotropic negative thermal expansion in Y-doped samarium monosulfides by intra-atomic charge transfer
复制标题
DOI：
10.1038/s41598-018-36568-w
复制
发表时间：
2019-01
影响因子：
4.6
通讯作者：
K. Takenaka;D. Asai;Ryoichi Kaizu;Y. Mizuno;Y. Yokoyama;Y. Okamoto;N. Katayama;H. Suzuki;Y. Imanaka
中科院分区：
文献类型：
--
作者：
K. Takenaka;D. Asai;Ryoichi Kaizu;Y. Mizuno;Y. Yokoyama;Y. Okamoto;N. Katayama;H. Suzuki;Y. Imanaka
在现代先进工业对热膨胀控制的强烈需求的刺激下，各种巨大的负热膨胀（NTE）材料在过去的十年中得到了发展。然而，大多数这类材料在晶格中表现出各向异性热膨胀。因此，在重复热循环过程中产生的应变和裂纹降低了它们作为热膨胀补偿器的性能。在这里，我们通过控制Sm (4f)6或（4f）5(5d)1中Sm原子的电子组态，通过用y部分替代Sm，实现了体积变化超过3%，最高达4.1%的巨大反各向异性NTE。与源于磁性等协同现象的NTE相反，目前归因于原子内现象的NTE避免了NTE的尺寸效应，因此为我们提供了细粒度的热膨胀补偿器。对于控制微区域的热膨胀，如三维集成电路的下填料是非常需要的。单硫化物镧系元素的体积控制通过调整四氟电子结构为材料的新型机械功能提供了途径，例如由电场驱动的体积变化驱动驱动器，它与传统的应变驱动驱动器（如压电致伸缩或磁致伸缩材料）具有不同的驱动原理。
Stimulated by strong demand for thermal expansion control from advanced modern industries, various giant negative thermal expansion (NTE) materials have been developed during the last decade. Nevertheless, most such materials exhibit anisotropic thermal expansion in the crystal lattice. Therefore, strains and cracks induced during repeated thermal cycling degrade their performance as thermal-expansion compensators. Here we achieved giantisotropicNTE with volume change exceeding 3%, up to 4.1%, via control of the electronic configuration in Sm atoms of SmS, (4f)6or (4f)5(5d)1, by partial replacement of Sm with Y. Contrary to NTE originating from cooperative phenomena such as magnetism, the present NTE attributable to theintra-atomicphenomenon avoids the size effect of NTE and therefore provides us with fine-grained thermal-expansion compensators, which are strongly desired to control thermal expansion of microregions such as underfill of a three-dimensional integrated circuit. Volume control of lanthanide monosulfides via tuning of the 4felectronic configuration presents avenues for novel mechanical functions of a material, such as avolume-changedriven actuator by an electrical field, which has a different drive principle from those of conventional strain-driven actuators such as piezostrictive or magnetostrictive materials.