Role of higher-order effects in spin-misalignment small-angle neutron scattering of high-pressure torsion nickel
Role of higher-order effects in spin-misalignment small-angle neutron scattering of high-pressure torsion nickel
复制标题
DOI：
10.1103/physrevmaterials.5.084410
复制
发表时间：
2021-05
影响因子：
3.4
通讯作者：
Y. Oba;M. Bersweiler;Ivan Titov;N. Adachi;Y. Todaka;E. Gilbert;N. Steinke;K. Metlov;A. Michels
中科院分区：
文献类型：
--
作者：
Y. Oba;M. Bersweiler;Ivan Titov;N. Adachi;Y. Todaka;E. Gilbert;N. Steinke;K. Metlov;A. Michels
磁场相关的非极化小角中子散射（SANS）实验表明，高压扭转（HPT）应变导致纯Ni的自旋失调，这种失调在高达4 t的磁场中持续存在。由于不寻常的纵向sin -型角各向异性，自旋失调散射模式垂直于外加磁场被拉长。在接近饱和状态下，这种贡献不能用传统的二阶（自旋失调幅度）微磁SANS理论来解释，也不能用三阶微磁SANS理论来解释其相对于横截面的其他特征的大小。这表明Ni中HPT应变引起的高密度晶体缺陷使得在微磁SANS截面上可以观察到这种高阶效应。
Magnetic-field-dependent unpolarized small-angle neutron scattering (SANS) experiments demonstrate that high-pressure torsion (HPT) straining induces spin misalignments in pure Ni, which persist in magnetic fields up to 4 T. The spin-misalignment scattering patterns are elongated perpendicular to the applied magnetic field due to an unusual predominant longitudinal sin-type angular anisotropy. Such a contribution cannot be explained by the conventional second order (in spin misalignment amplitude) micromagnetic SANS theory in the approach-to-saturation regime, nor can its magnitude relative to the other features of the cross sections by the third order micromagnetic SANS theory. This indicates that the high-density of crystal defects induced via HPT straining in Ni makes such higher-order effects in the micromagnetic SANS cross sections observable.