Periodic order and defects in Ni-based inverse opal-like crystals on the mesoscopic and atomic scale

Abstract

The structure of inverse opal crystals based on nickel was probed on the mesoscopic and atomic levels by a set of complementary techniques such as scanning electron microscopy and synchrotron microradian and wide-angle diffraction. The microradian diffraction revealed the mesoscopic-scale face-centered-cubic (fcc) ordering of spherical voids in the inverse opal-like structure with unit cell dimension of 750 ± 10 nm. The diffuse scattering data were used to map defects in the fcc structure as a function of the number of layers in the Ni inverse opal-like structure. The average lateral size of mesoscopic domains is found to be independent of the number of layers. 3D reconstruction of the reciprocal space for the inverse opal crystals with different thickness provided an indirect study of original opal templates in a depth-resolved way. The microstructure and thermal response of the framework of the porous inverse opal crystal was examined using wide-angle powder x-ray diffraction. This artificial porous structure is built from nickel crystallites possessing stacking faults and dislocations peculiar for the nickel thin films.

Temperature behavior of the local magnetization vectors in ferromagnetic inverted opal-like structures

“…The fig ure shows that with this method of synthesis, the inverted and solid ferromagnetic films are deposited in the form of granules from 50 to 200 nm in size. The scanning electron microscopy data are confirmed by diffraction measurements [26], in which the size of the coherent scattering region in the IOLS was estimated from the broadening of Bragg reflections in the pow der diffraction pattern of the ferromagnetic filling material, and also found to be 50 to 200 nm.…”

“…It is seen that as the temperature changes, the shape of the remagnetization curve alters significantly, and, therefore, the values of critical fields change. The dependence of the critical fields H C , H C1 , H C2 , H C3 on temperature for IOLS Ni 26 and Co 26 are shown in Fig. 6.…”

Magnetic structure of the inverse opal-like structures: Small angle neutron diffraction and micromagnetic simulations

“…Spatial ordering of the sample on the mesoscale was investigated by microradian x-ray diffraction technique. Details of data acquisition and treatment can be found elsewhere [2,3,41,42].…”

Исследование Квазидвумерных И Квазитрехмерных Упорядоченных Пористых Структур Методами Малоугловой Дифракции В Скользящей Геометрии

“…Методом малоуглового рассеяния синхротронного из-лучения было показано, что коллоидные кристаллы [47] и инвертированные на их основе опалы [10,33,48] имеют двойникованную ГЦК-структуру.…”

“…Наличие на картине дифракции низкоинтенсивных максимумов характерных для гекса-гональной плотной упаковки (отмечены квадратом на рис. 15, b) связано с малыми толщинами исследуемых инвертированных опалов [37,48].…”