Recent Developments in the X-Ray Reflectivity Analysis for Rough Surfaces and Interfaces of Multilayered Thin Film Materials

Fujii, Yoshikazu

doi:10.1155/2013/678361

Cited by 5 publications

(3 citation statements)

References 20 publications

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“…XRR is widely used to determine thickness, density and roughness of multilayer stacks on different types of crystalline and amorphous materials. 44,45 The incident angle of X-rays for XRR is varied a few degrees above and below the critical angle of reflection of the material under study. For a flat surface, the reflectivity shows a sudden decrease above the critical angle in proportion to θ X −4 , whereas for a rough surface, the reflectivity decays in a faster manner.…”

Section: X-ray Reflectivity (Xrr)mentioning

confidence: 99%

Understanding properties of engineered catalyst supports using contact angle measurements and X-Ray reflectivity

et al. 2016

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There is significant interest in broadening the type of catalyst substrates that support the growth of high-quality carbon nanotube (CNT) carpets. In this study, ion beam bombardment has been utilized to modify catalyst substrates for CNT carpet growth. Using a combination of contact angle measurements (CAMs) and X-ray reflectivity (XRR) for the first time, new correlations between the physicochemical properties of pristine and engineered catalyst substrates and CNT growth behavior have been established. The engineered surfaces obtained after exposure to different degrees of ion beam damage have distinct physicochemical properties (porosity, layer thickness, and acid-base properties). The CAM data were analyzed using the van Oss-Chaudhury-Good model, enabling the determination of the acid-base properties of the substrate surfaces. For the XRR data, a Fourier analysis of the interference patterns enabled extraction of layer thickness, while the atomic density and interfacial roughness were extracted by analyzing the amplitude of the interference oscillations. The dramatic transformation of the substrate from "inactive" to "active" is attributed to a combined effect of substrate porosity or damage depth and Lewis basicity. The results reveal that the efficiency of catalyst substrates can be further improved by increasing the substrate basicity, if the minimum surface porosity is established. This study advances the use of a non-thermochemical approach for catalyst substrate engineering, as well as demonstrates the combined utility of CAM and XRR as a powerful, nondestructive, and reliable tool for rational catalyst design.

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Section: X-ray Reflectivity (Xrr)mentioning

confidence: 99%

Understanding properties of engineered catalyst supports using contact angle measurements and X-Ray reflectivity

et al. 2016

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“…To obtain reliable data on the buried layers, we used the X-ray reflectivity (XRR) technique, which is well established and recognized for analysis of interface properties with subangstrom precision. , The XRR spectra were fitted using the standard procedure to obtain the interface parameters, including the average roughness amplitude of the entire sample (which is statistical) and the intermixing depth at each interface. The experimental and simulated XRR spectra for the sample with t W = 0.25 nm annealed at different temperatures are shown in Figure a.…”

Section: Resultsmentioning

confidence: 99%

Thermal Annealing Driven Enhancement of Perpendicular Magnetic Anisotropy and the Interfacial Dzyaloshinskii–Moriya Interaction in Ultrathin Ru/Co/W/Ru Films

Samardak

Kolesnikov

Stebliy

et al. 2023

ACS Appl. Electron. Mater.

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Spin-related effects discovered in ultrathin magnetic films generally have an interfacial nature. The quality of interfaces between a heavy metal and a ferromagnet is the main driver of surface anisotropy, antisymmetric exchange, chiral damping, spin Hall effect, and spin−orbit torques. To understand the physics and usage of these phenomena for future atomic-scale devices, one has to study systems with disordered interfaces and search there for novel practically desirable effects, which lie beyond the atomic order and surface flatness. Here, we report the interface-related effects in Ru/Co/W/Ru ultrathin films treated by thermal annealing in vacuum. The surface roughness and degree of atomic intermixing at Ru/Co and Co/W interfaces change with increasing annealing temperature up to 240 °C, promoting an enhancement of perpendicular magnetic anisotropy and the interfacial Dzyaloshinskii−Moriya interaction (i-DMI). Further annealing at higher temperatures brings the interface deterioration and, consequently, a drastic degradation of the magnetic properties. Our first-principles calculations qualitatively support the experimental findings, providing an understanding of the i-DMI enhancement nature.

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“…[1][2][3][4] Neuhold et al proved that x-ray reflectivity is an excellent tool to investigate buried interfaces in organic electronic devices 5 although the interpretation of XRR measurements depends on a large number of parameters such as thickness and roughness and is therefore difficult. 1 Theoretical considerations discuss the influence of roughness in layer stacks 6,7 and demonstrate the impact of the roughness with decreasing thickness of the layers.…”

Section: Introductionmentioning

confidence: 99%

Determination of layer morphology of rough layers in organic light emitting diodes by X‐ray reflectivity

Sachs

Fuhrmann

Deferme

et al. 2022

Engineering Reports

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X-ray reflectivity (XRR) has been proven to be a useful tool to investigate thin layers as well as buried interfaces in stacks built of very thin layers. Nevertheless, x-ray reflectivity measurements are limited by the roughness of the layers and interfaces as the roughness destroys the interference structure, the so-called Kiessig fringes. As investigations of thin layers in organic light emitting devices (OLEDs) are still subject of research and development, the focus of this paper is the investigation of a layer of indium tin oxide (ITO) which serves as transparent anode material in OLEDs. Due to the fabrication process, ITO shows rough surface structures, so-called spikes, hindering the determination of the ITO layer thickness and roughness in XRR measurements. In this paper, it is theoretically and experimentally proven that a smoothing layer on the ITO enables the determination of the buried ITO layer thickness and roughness as well as the density of the spikes. Furthermore, a sputtered aluminum layer (e.g. cathode material) showing spikes in atomic force microscopy covered with a smoothing layer reveals Kiessig fringes allowing the determination of the density of buried spikes. In general, it is shown that a smoothing layer on a rough surface enhances the sensitivity of x-ray reflectivity measurements.

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Recent Developments in the X-Ray Reflectivity Analysis for Rough Surfaces and Interfaces of Multilayered Thin Film Materials

Cited by 5 publications

References 20 publications

Understanding properties of engineered catalyst supports using contact angle measurements and X-Ray reflectivity

Understanding properties of engineered catalyst supports using contact angle measurements and X-Ray reflectivity

Thermal Annealing Driven Enhancement of Perpendicular Magnetic Anisotropy and the Interfacial Dzyaloshinskii–Moriya Interaction in Ultrathin Ru/Co/W/Ru Films

Determination of layer morphology of rough layers in organic light emitting diodes by X‐ray reflectivity

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