Element-selective elastic properties of Fe65Ni35 Invar alloy and Fe72Pt28 alloy studied by extended X-ray absorption fine structure
Element-selective elastic properties of Fe65Ni35 Invar alloy and Fe72Pt28 alloy studied by extended X-ray absorption fine structure
复制标题
扩展X射线吸收精细结构研究Fe65Ni35 Invar合金和Fe72Pt28合金的元素选择性弹性性能
DOI：
10.1080/08957959.2019.1702175
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发表时间：
2019
影响因子：
2
通讯作者：
Irifune T.
中科院分区：
文献类型：
--
作者：
Kousa M.;Iwasaki S.;Ishimatsu N.;Kawamura N.;Nomura R.;Kakizawa S.;Mizumaki M.;Sumiya H.;Irifune T.
作为纳米多晶金刚石（NPD）在扩展X射线吸收精细结构（EXAFS）研究中的一个新应用，我们提出了高压下铁磁FeNiInvar合金和FePtalloy的元素选择性局域结构分析。因瓦效应是一种在很宽的温度范围内热膨胀几乎为零的现象。FePt是一种表现出负热膨胀的合金。我们的EXAFS分析成功揭示了Fe和Ni/Pt周围局部结构之间元素选择性弹性性质的显着差异。Fe周围的局部结构具有比Ni小的体积模量。因此，Fe周围更多的压缩行为是造成因瓦合金特有的超软弹性特性的原因。在FePt的情况下，Fe具有比Pt小的体积模量;然而，与因瓦合金相比，铁磁相中的体积模量的差异小。我们还报告了不同的趋势，压力引起的德拜-沃勒因素减少顺磁相。
We present the element-selective local structure analysis of ferromagnetic FeNiInvar alloy and FePtalloy under high pressures as a recent application of nano-polycrystalline diamond (NPD) to extended X-ray absorption fine structure (EXAFS). The Invar effect is a phenomenon where thermal expansion becomes nearly zero in a wide range of temperatures. FePtis an alloy exhibiting negative thermal expansion. Our EXAFS analysis successfully revealed significant differences in element-selective elastic properties between local structures around Fe and Ni/Pt. The local structure around Fe has a smaller bulk modulus than that of Ni. Hence, the more compressive behavior around Fe is responsible for the anomalously soft elastic property that is characteristic of Invar alloy. In the case of FePt, Fe has a smaller bulk modulus than Pt; however, the difference in bulk modulus in the ferromagnetic phase is small compared with that of Invar alloy. We also report different trends of pressure-induced decrease in Debye-Waller factors toward paramagnetic phases.