Structural and magnetic properties of inverse opal photonic crystals studied by x-ray diffraction, scanning electron microscopy, and small-angle neutron scattering
Structural and magnetic properties of inverse opal photonic crystals studied by x-ray diffraction, scanning electron microscopy, and small-angle neutron scattering
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通过 X 射线衍射、扫描电子显微镜和小角中子散射研究反蛋白石光子晶体的结构和磁性
DOI：
10.1103/physrevb.79.045123
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
H. Eckerlebe
中科院分区：
文献类型：
--
作者：
S. Grigoriev;K. Napolskii;N. A. Grigoryeva;A. V. Vasilieva;A. Mistonov;D. Chernyshov;A. Petukhov;D. V. Belov;A. Eliseev;A. Lukashin;Y. Tret’yakov;A. Sinitskii;H. Eckerlebe
通过扫描电子显微镜、同步加速器辐射的广角和小角衍射以及偏振中子等补充实验技术研究了镍反蛋白石光子晶体的结构和磁性。该样品是通过将镍电化学沉积在由 450 nm 聚苯乙烯微球制成的胶体晶体膜的空隙中，然后将其溶解在甲苯中而制成的。利用同步辐射的微弧度小角衍射揭示了类蛋白石的大尺度有序性，证明了其倾向于面心立方面心立方结构，晶格常数为65010 nm。广角X射线粉末衍射表明，形成反蛋白石骨架的纳米尺寸fcc镍微晶在宏观尺度上具有由反蛋白石主方向规定的一些织构，从而表明原子结构和宏观结构是相关的。极化小角度中子散射在其检测施加场下磁结构转变的能力的极限上被使用。分析了中子散射的不同贡献：非磁性核散射、纯磁性散射和核磁干扰。衍射图案中的后者显示了磁反射平面和核反射平面之间的空间相关程度，并给出了这些平面的反转磁化过程的图案行为。纯磁贡献的场依赖性表明，结构的三维几何形状可能导致样品中磁化强度的复杂分布。
The structural and magnetic properties of nickel inverse opal photonic crystal have been studied by complementary experimental techniques, including scanning electron microscopy, wide-angle and small-angle diffraction of synchrotron radiation, and polarized neutrons. The sample was fabricated by electrochemical deposition of nickel in voids in a colloidal crystal film made of 450 nm polystyrene microspheres followed by their dissolving in toluene. The microradian small-angle diffraction of synchrotron radiation was used to reveal the opal-like large-scale ordering proving its tendency to the face-centered-cubic fcc structure with the lattice constant of 65010 nm. The wide-angle x-ray powder diffraction has shown that nanosize fcc nickel crystallites, which form an inverse opal framework, have some texture prescribed by principal directions in inverse opal on a macroscale, thus showing that the atomic and macroscopic structures are correlated. The polarized small-angle neutron scattering is used on the extreme limit of its ability to detect the transformation of the magnetic structure under applied field. Different contributions to the neutron scattering have been analyzed: the nonmagnetic nuclear one, the pure magnetic one, and the nuclear-magnetic interference. The latter in the diffraction pattern shows the degree of the spatial correlation between the magnetic and nuclear reflecting planes and gives the pattern behavior of the reversal magnetization process for these planes. The field dependence of pure magnetic contribution shows that the three-dimensional geometrical shape of the structure presumably leads to a complex distribution of the magnetization in the sample.