Grazing Incidence X-ray Diffraction Research Articles

Effect of Annealing on Stress, Microstructure, and Interfaces of NiV/B4C Multilayers

The functionality and reliability of nanoscale multilayer devices and components are influenced by changes in stress and microstructure throughout fabrication, processing, and operation. NiV/B4C multilayers with a d-spacing of 3 nm were prepared by magnetron sputtering, and two groups of annealing experiments were performed. The stress, microstructure, and interface changes in NiV/B4C after annealing were investigated by grazing-incidence X-ray reflectometry (GIXR), grazing-incidence X-ray diffraction (GIXRD), X-ray diffuse scattering, and grazing-incidence small-angle X-ray scattering (GISAXS). The temperature dependence experiments revealed a gradual shift in the multilayer stress from compression to tension during annealing from 70 °C to 340 °C, with the stress approaching near-zero levels between 70 °C and 140 °C. The time-dependent experiments indicated that most of the stress changes occurred within the initial 10 min, which showed that prolonged annealing was unnecessary. Combining the X-ray diffraction and X-ray scattering measurements, it was found that the changes in the thickness, interface roughness, and lateral correlation length, primarily due to crystallization, drove the changes in stress and microstructure.

Modification induced by 120 MeV Ag ion irradiation in ZnS

We report the structural, morphological, and optical properties of ZnS thin films before and after swift heavy ion (SHI) irradiation of 120 MeV Ag ions. These films were deposited by the spin coating method on the glass substrate and irradiated at various ion fluencies from 1 × 1011 to 1 × 1013 ions/cm2. The Grazing Incidence X-ray diffraction (GIXRD), Scanning electron microscopy (SEM), UV–visible transmittance, Photoluminescence (PL), and Raman Spectroscopy were used to characterize these ZnS thin films. The GIXRD patterns show a mixed phase of cubic and hexagonal structure after the ion irradiation. The crystallite sizes of pure and irradiated films are significantly modified. Raman spectroscopy shows a slight increase in the intensity of the 3LO mode of ZnS on irradiation. The SEM image shows nanoflake-like structures in pristine, and the irradiated thin films depict various morphologies (rod, platy, and sphere-like). UV–visible shows a cut-off wavelength at 339 nm and the spectra are blue-shifted with the increase in ion fluence. The Tauc plots reveal the increase in the band gap. The intensity of PL decreases with ion irradiation. Hence the analytical results show that the structural and optical properties of ZnS thin films are altered on swift heavy ion irradiation which may have potential applications in optoelectronic applications.

Aggregation induced strong photoluminescence at room temperature in large-area C8BTBT thin films

Study of optical properties of 2,7-dioctyl[1]benzothieno[2,3-b]benzothiophene (C8BTBT) is promising for applications in low-cost and flexible optoelectronic devices. Here, we systematically investigated the thickness dependent structural and photophysical properties of large-area C8BTBT films. The large-area C8BTBT thin films of different thickness below 80 nm were prepared by off-centre spin coating method. Grazing incidence X-ray diffraction measurements confirm the highly crystalline nature of the thin films and reveal that crystal coherence length increases with increase of film thickness. The film morphology and its thickness were studied using atomic force microscopy. Further, optical absorption and emission behaviors of the thin films were analyzed. The results show strong ultraviolet (UV) emissions at room temperature. The photoluminescence behaviour of higher-thickness films differs from that of lower-thickness films. The thickness dependent UV emission spectra are explained in terms of defects and aggregation behavior of C8BTBT thin films. We determine the impact of thickness and aggregation (J- and H-type) on emission behaviors of the C8BTBT thin films. Our findings open a new avenue for the future optimization and prospective applications in photonics based on two-dimensional organic semiconductors.

Transistors with ferroelectric ZrXAl1−XOY crystallized by ZnO growth for multi-level memory and neuromorphic computing

Ferroelectric (FE) field-effect transistors are interesting for their non-destructive readout characteristic and energy efficiency but are difficult to integrate on silicon platforms. Here, FE ZrXAl1−XOY (ZAO) is demonstrated by compressive strain in contact with ZnO. The metal-ferroelectric-semiconductor-metal capacitor exhibits a substantial remnant polarization of 15.2 µC cm−2, along with a bowknot-like anti-clockwise hysteresis in the capacitance curves. The FE-ZAO gated ZnO thin-film transistor presents a large memory window (3.84 V), low subthreshold swing (55 mV dec−1), high ION/IOFF ratio (≈108), and low off-state current (≈1 pA). The grazing incidence X-ray diffraction and scanning transmission electron microscopy analyses reveal the ferroelectric rhombohedral phase (space group R3m) in the nanocrystal ZAO, containing an angle of ≈71.7° between the [111] and [11-1] directions with d111-spacing of 3.037 Å and d11-1-spacing of 2.927 Å. Finally, the memory and neuromorphic applications are analyzed by demonstrating multi-level memory and synaptic weight performance with a high learning accuracy of 91.82%.

Annealing-induced defects and optical degradation in sputter-deposited silicon nitride: Implications for photonic applications

Silicon nitride (SiNx) is a critical material for advanced photonic applications. This study investigates the effect of annealing on sputter-deposited silicon nitride. The results demonstrate that blisters and holes appear in annealed SiNx, which compromise its integrity and lead to increased roughness. These defects are closely related to the annealing process. Specifically, the blister diameter expands from 5.17 μm at 600 °C to more than 25 μm at 800 °C. Additionally, the defect ratio increases significantly from 1.25 % to 14.82 % for full annealing. Rapid thermal annealing induces a 12 % defect ratio and a surface roughness of 13.1 nm. X-ray photoelectron spectroscopy results suggest that defects originate from unsaturated silicon sites, particularly in silicon-rich SiNx. Raman spectroscopy reveals a blueshift in the silicon peak after annealing, indicating biaxial tensile stress applied to the coatings, which is supported by the diffraction peaks observed in grazing incidence X-ray diffraction patterns. This mechanical stress may contribute to blistering and bursting. Moreover, annealing significantly alters the refractive index and dispersion properties of SiNx, with transmission losses reaching up to 20 %, presenting a considerable challenge for photonic applications. Notably, the performance of silicon nitride-based Bragg reflectors deteriorates markedly after annealing. This study elucidates the balance between annealing conditions and their effects on sputter-deposited silicon nitride, ensuring its continued viability in the rapidly expanding field of photonics.

Si(111) islands on β-phase Si(111)√3 × √3R30°-Bi

β-phase √3 × √3R30°-bismuth (Bi) on silicon (Si)(111)7 × 7 surface has been exploited as a template for growing Si films. Two-dimensional Si islands with √3 × √3 reconstruction, parallel to that of Si(111)√3 × √3R30°-Bi, have been resolved by means of scanning tunneling microscopy, grazing-incidence X-ray diffraction (XRD) and low electron energy diffraction. Auger electron spectroscopy and scanning tunneling spectroscopy gave interesting electronic features on two-dimensional Si islands, with the evidence of a reduced band gap to ~0.55 eV, related to the presence of the underneath Bi layer, and atomic structural properties typical of Si(111). These experimental findings fully confirm the recently reported calculation based on the first-principles density functional theory, on the prediction of Si(111) growth on top of β-phase √3 × √3R30°-Bi/Si(111)7 × 7 reconstruction, shedding new light on silicon structures.

The impact of post-deposition annealing durations on the formation of Tb4O7 passivation layer on silicon substrate

In this study, we have effectively utilized radio frequency (RF) sputtering to sputter the Tb4O7 passivation layer on an n-type silicon (Si) substrate in an argon (Ar) ambient. Various characterization approaches were used to investigate the impact of varying annealing durations on structural, morphological, compositional, and optical properties. The grazing incidence X-ray diffraction (GIXRD) pattern confirmed that all investigated Tb4O7 passivation layers (as grown) and annealed at (15, 30, and 45 min) showed a crystalline structure, respectively. As observed, the sample annealed for 30 min attained the highest crystallinity, around 39.51 nm. Surface morphology analysis revealed different surface structures in response to different annealing durations when observed using the field emission scanning electron microscopy (FESEM) technique. Atomic force microscopy (AFM) was utilized to investigate the top surface of the examined samples, and a higher surface roughness of around 2.37 nm was obtained for the sample annealed for 30 min. The band gap energies (Eg) were estimated by applying the Kubelka-Munk (KM) approach for all the investigated samples, and the obtained values were within a range between (1.94–3.07 eV) earlier reported in the literature. Previous studies have shown that the Tb4O7 passivation layer deposited onto Si substrates using RF sputtering and then annealed for 5 min at 900 °C in an Ar atmosphere, resulted in the formation of a highly crystalline passivation layer. However, there is a lack of a clear explanation for the observation, and the authors mainly concentrated on the electrical properties of the Tb4O7 material. This inspired us to carry out this study to investigate the impact of various annealing durations on the formation of Tb4O7 passivation layers, focusing on their structure, composition, morphology, and optical properties.

Effects of multilayer structure on the high-speed dry-cutting performance of AlCrBN/AlCrN multilayer coatings

To investigate the effects of different structures on the cutting performance of AlCrBN/AlCrN multilayer coatings, AlCrBN/AlCrN coatings with different multilayer structures (single layer, 10 bilayers, and 20 bilayers corresponding to T1 coating, T10 coating, and T20 coating) were synthesized using multi-arc ion plating technology. Grazing incidence X-ray diffraction (GIXRD) and transmission electron microscopy (TEM) results showed that the coatings were mainly composed of fcc-(Cr, Al) N phases located on the (111) and (200) crystal planes. All coatings exhibited a good indentation adhesion to the substrates. The hardness of the T10 coating (32.6 GPa) and T20 coating (31.2 GPa) was significantly higher than that of the T1 coating (28.0 GPa). Annealing experiments show that no phase composition evolution was revealed at 800 °C. High-speed milling tests imply that the milling life of the T10 coating (13 m) and the T20 coating (10 m) was increased by 62.5% and 25.0% compared to the T1 coating (8 m), respectively. In high-speed dry turning tests, the T10 coated tool also showed the longest lifetime (16 mins), an improvement of 23.1% over T1 or T20 coated tools (13 mins). SEM analyses of wear coated tools indicated that a multilayer structure enhanced their resistance to abrasion and adhesion wear, and led to better cutting performance, probably because of their excellent mechanical properties and thermal stability.

Thin-film photodiode based on novel SiC/MoS2 composite by RF-sputtering for fast response photodetection

A Schottky -photodiode and pn-photodiode were fabricated based on a SiC/MoS2 composite semiconductor material using a physical vapour deposition (PVD) method. The surface topology and structural features of the nanostructured SiC/MoS2 thin films were investigated using scanning electron microscope (SEM), Fourier Transform Infrared spectroscopy (FTIR), and grazing incidence X-Ray diffraction (GIXRD) analysis. The two-dimensional nature of these materials enables easiness integration for vertical device design with novel properties. The performance parameters of the fabricated devices were characterized. The electrical performance of the fabricated SiC/MoS2 Schottky and pn photodiodes were investigated according to their current-voltage (I–V) characteristics within a bias voltage range from −4 to 4 V. Here, we report highly efficient photocurrent generation from vertical SiC/MoS2 composite device fabricated using asymmetric metal contacts, exhibiting an external quantum efficiency (EQE) of up to 14.68% for pn -photodiode and 6.68% for Schottky -photodiode. Evaluated to in-plane MoS2 devices, the vertical design of these devices has a much larger junction area which is essential for achieving highly efficient photovoltaic devices. As well as spectral responsivity of 28.25 mA/W and 63.22 mA/W for Schottky and pn-photodiodes respectively also, response time of 1 ms for Schottky-photodiode and 977.5 μs for pn-photodiode were measured and discussed.

Effects of electrodes on antiferroelectricity and fatigue endurance of Hf0.2Zr0.8O2 thin films

The influence of electrodes on antiferroelectricity and fatigue endurance of 15 nm thick Hf0.2Zr0.8O2 thin films has been studied by a metal–antiferroelectric–metal capacitor structure using TiN and W as electrodes. The W|Hf0.2Zr0.8O2|W capacitor shows significantly enhanced antiferroelectricity and better endurance compared to the capacitor using TiN as the electrode. Assisted by grazing incidence x-ray diffraction and scanning transmission electron microscopy, the different electrical properties are discussed based on the contents of different phases and the diffusion of oxygen from the thin film into electrodes.

Mechanical and Tribological Properties of CrWN/MoN Nano-Multilayer Coatings Deposited by Cathodic Arc Ion Plating

CrWN/MoN nano-multilayer coatings were deposited in pure N2 by multi-arc ion plating using CrW and Mo targets, with the cathode co-controlled by a permanent magnet combined with an electromagnet. The effects of the thickness modulation period on the microstructure and mechanical and tribological performance were systematically analyzed by grazing-incident X-ray diffraction (GIXRD), transmission electron microscopy (TEM), Nanoindentation, scanning electron microscope (SEM) and profilometry using a Talysurf profilometer. The local coherent interfaces and nanoscale modulation period were confirmed by TEM, while the coatings were confirmed to be composed of fcc-CrWN and hexagonal δ-MoN by GIXRD. With the increase in the modulation period, the hardness of the CrWN/MoN nano-multilayer coatings decreased, and the values of the H/E ratio and friction coefficient showed the same variation trend. At an 8.0 nm modulation period, the CrWN/MoN nano-multilayer coating showed the maximum hardness (30.2 GPa), the lowest H/E value (0.082) and an H3/E*2 value of 0.16. With the decrease in the modulation period, the average friction coefficient of the CrWN/MoN nano-multilayer coatings gradually decreased from 0.45 to 0.29, while the wear rate decreased from 4.2 × 10−7 mm3/Nm to 3.3 × 10−7 mm3/Nm.

Deposition of alternative plasmonic ZrHfN thin films via closed-field dual-cathode DC unbalanced magnetron sputtering for enhanced SEF substrate applications

We present the preparation of zirconium hafnium nitride thin films as an alternative plasmonic sensing material. The ZrHfN thin films were deposited by closed-field dual-cathode DC unbalanced magnetron sputtering without an external substrate heating/biasing. A comprehensive investigation into the effect of zirconium sputtering current on the physical structural, and chemical compositions was systematically characterized by grazing-incidence X-ray diffraction, transmission electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy. Our results indicate that the optimal ZrHfN thin films deposited at 500 mA-IZr exhibit good crystallinity and high surface roughness, which presents excellent surface-enhanced fluorescent substrate performance for detecting rhodamine 6G at a limit of detection of 5.99 × 10−8 M, an enhancement factor of 15.62 ± 0.79-fold and displaying reusability through 25 cycles. These findings suggest promising prospects for developing ZrHfN-based SEF sensor chips for diverse applications in the future.

Influence of thermal annealing on microstructure, energetic landscape and device performance of P3HT:PCBM-based organic solar cells

Thermal annealing alters the morphology of organic donor-acceptor bulk-heterojunction thin films used in organic solar cells. Here, we studied the influence of thermal annealing on blends of amorphous regio-random (RRa) and semi-crystalline regio-regular (RR) poly (3-hexylthiophene) (P3HT) and the fullerene derivative [6,6]-phenyl-C60-butyric acid methyl ester. Since the P3HT:PCBM blend is one of the most studied in the OPV community, the existing research provides a solid foundation for us to compare and benchmark our innovative characterization techniques that have been previously under-utilized to investigate bulk heterojunction organic thin films. Here, we combine advanced novel microscopies and spectroscopies, including polarized light microscopy, photo-deflection spectroscopy, hyperspectral photoluminescence imaging, and energy resolved-electrochemical impedance spectroscopy, with structural characterization techniques, including grazing-incidence wide-angle x-ray scattering, grazing-incidence x-ray diffraction, and Raman spectroscopy, in order to reveal the impact of thermal annealing on the microstructural crystallinity and morphology of the photoactive layer in organic solar cells. Coupled transfer matrix and drift-diffusion simulations were used to study the impact of the density of states on the solar cells’ device performance parameters, namely the short-circuit current (J SC), open circuit voltage (V OC), fill factor (FF), and power conversion efficiency (PCE).

Correlation between the micro-shot peening coverage and surface microstructural evolution and fluoride-induced corrosion behavior in Monel 400 alloy

This study examines the influence of micro-shot peening (MSP) on Monel 400 alloy, focusing on surface microstructural evolution and fluoride-induced corrosion behavior compared to its solution annealed (SAed) counterpart. MSP treatments were conducted at various surface coverages (100%, 200%, 500%, 1000%, 1500%, and 2000%). Characterization encompassed microhardness, surface roughness, grazing incidence x-ray diffraction (GI-XRD), field emission scanning electron microscopy (FE-SEM) with electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). With increasing the MSP coverage to 2000%, the surface crystallite size decreased from approximately ∼30 µm in the SAed sample to 60 nm. TEM analysis emphasized dislocation slip and formation of dislocation structures as the primary mechanisms for the grain refinement. However, the 2000% coverage exhibited microcrack formation, compromising its hydrofluoric (HF) corrosion resistance. Electrochemical tests revealed severe localized corrosion in all MSP-treated samples except the 1500% coverage, which exhibited a minimum passive current density of 0.2–1.0 µA/cm2. Inductively coupled plasma optical emission spectroscopy (ICP-OES) of immersion solutions showed lower copper and nickel ion concentrations (<150 ppm) in the 1500% MSP-treated sample, indicating its enhanced corrosion resistance. X-ray photoelectron spectroscopy (XPS) identified NiO, NiF2, CuO, CuF2, and Cu(OH)2 phases in SAed and 1500% MSPed samples, with a higher concentration of copper oxide (CuO) in the corrosion film of the 1500% MSP-treated sample, contributing to its superior corrosion resistance.

Structure of liquid-vapor interfaces: Perspectives from liquid state theory, large-scale simulations, and potential grazing-incidence x-ray diffraction.

Grazing-incidence x-ray diffraction (GIXRD) is a scattering technique that allows one to characterize the structure of fluid interfaces down to the molecular scale, including the measurement of surface tension and interface roughness. However, the corresponding standard data analysis at nonzero wave numbers has been criticized as to be inconclusive because the scattering intensity is polluted by the unavoidable scattering from the bulk. Here, we overcome this ambiguity by proposing a physically consistent model of the bulk contribution based on a minimal set of assumptions of experimental relevance. To this end, we derive an explicit integral expression for the background scattering, which can be determined numerically from the static structure factors of the coexisting bulk phases as independent input. Concerning the interpretation of GIXRD data inferred from computer simulations, we extend the model to account also for the finite sizes of the bulk phases, which are unavoidable in simulations. The corresponding leading-order correction beyond the dominant contribution to the scattered intensity is revealed by asymptotic analysis, which is characterized by the competition between the linear system size and the x-ray penetration depth in the case of simulations. Specifically, we have calculated the expected GIXRD intensity for scattering at the planar liquid-vapor interface of Lennard-Jones fluids with truncated pair interactions via extensive, high-precision computer simulations. The reported data cover interfacial and bulk properties of fluid states along the whole liquid-vapor coexistence line. A sensitivity analysis shows that our findings are robust with respect to the detailed definition of the mean interface position. We conclude that previous claims of an enhanced surface tension at mesoscopic scales are amenable to unambiguous tests via scattering experiments.

Understanding the Retention of Vaping Additives in the Lungs: Model Lung Surfactant Membrane Perturbation by Vitamin E and Vitamin E Acetate.

Deviations from the normal physicochemical and functional properties of pulmonary surfactants are associated with the incidence of lung injury and other respiratory disorders. This study aims to evaluate the alteration of the 2D molecular organization and morphology of pulmonary surfactant model membranes by the electronic cigarette additives α-tocopherol (vitamin E) and α-tocopherol acetate (vitamin E acetate), which have been associated with lung injury, termed e-cigarette or vaping-use-associated lung injury (EVALI). The model membranes used contained a 7:3 molar ratio of DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) and POPG (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol) to which α-tocopherol and α-tocopherol acetate were added to form mixtures of up to 20 mol % additive. The properties of the neat tocopherol additives and DPPC/POPG (7:3) mixtures with increasing molar proportions of additive were evaluated by surface pressure-area isotherms, excess area calculations, Brewster angle microscopy, grazing incidence X-ray diffraction, X-ray reflectivity, and atomic force microscopy. The addition of either additive alters the essential phase balance of the model pulmonary surfactant membrane by generating a greater proportion of the fluid phase. Despite this net fluidization, both tocopherol additives have space-filling effects on the liquid-expanded and condensed phases, yielding negative excess areas in the liquid-expanded phase and reduced tilt angles in the condensed phase. Both tocopherol additives alter the stability of the fluid phase, pushing the eventual collapse of this phase to higher surface pressures than the model membrane in the absence of an additive.

Structural, chemical, and metal-oxide-semiconductor characteristics of RF magnetron sputtered thulium oxide passivation layer on 4H-silicon carbide substrate

Thulium oxide (Tm2O3) passivation layer (PL) deposited on 4H-silicon carbide (SiC) that was subjected to postdeposition annealing at 700 °C in forming gas-oxygen-forming gas ambient was reported for the first time in this work. X-ray photoelectron spectroscopy characterization revealed the success of annealing process in minimizing the concentration of oxygen vacancies and also curbed the presence of TmO suboxide bonding in the annealed Tm2O3 PL. In addition, XPS characterization has also disclosed the incorporation of nitrogen ions into the Tm2O3 lattice through the annealing process in which grazing incidence X-ray diffraction has also revealed the shift of detected peaks with regards to Tm2O3 phases to small diffraction angles. Although X-ray reflectivity measurements have disclosed the formation of thicker SiO2 interfacial layer (IL) for the annealed Tm2O3 PL, the acquisition of a higher dielectric constant (k) by the annealed PL when compared to as-deposited PL has suggested that the formation of SiO2 IL has minimal effect toward the k value of annealed PL. Metal-oxide-semiconductor characteristics of the annealed Tm2O3 PL on 4H-SiC was systematically reported in this letter.

Structural Parameters and Behavior in Simulated Body Fluid of High Entropy Alloy Thin Films.

The structure, composition and corrosion properties of thin films synthesized using the Pulsed Laser Deposition (PLD) technique starting from a three high entropy alloy (HEA) AlCoCrFeNix produced by vacuum arc remelting (VAR) method were investigated. The depositions were performed at room temperature on Si and mirror-like polished Ti substrates either under residual vacuum (low 10-7 mbar, films denoted HEA2, HEA6, and HEA10, which were grown from targets with Ni concentration molar ratio, x, equal to 0.4, 1.2, and 2.0, respectively) or under N2 (10-4 mbar, films denoted HEN2, HEN6, and HEN10 for the same Ni concentration molar ratios). The deposited films' structures, investigated using Grazing Incidence X-ray Diffraction, showed the presence of face-centered cubic and body-centered cubic phases, while their surface morphology, investigated using scanning electron microscopy, exhibited a smooth surface with micrometer size droplets. The mass density and thickness were obtained from simulations of acquired X-ray reflectivity curves. The films' elemental composition, estimated using the energy dispersion X-ray spectroscopy, was quite close to that of the targets used. X-ray Photoelectron Spectroscopy investigation showed that films deposited under a N2 atmosphere contained several percentages of N atoms in metallic nitride compounds. The electrochemical behavior of films under simulated body fluid (SBF) conditions was investigated by Open Circuit Potential (OCP) and Electrochemical Impedance Spectroscopy measurements. The measured OCP values increased over time, implying that a passive layer was formed on the surface of the films. It was observed that all films started to passivate in SBF solution, with the HEN6 film exhibiting the highest increase. The highest repassivation potential was exhibited by the same film, implying that it had the highest stability range of all analyzed films. Impedance measurements indicated high corrosion resistance values for HEA2, HEA6, and HEN6 samples. Much lower resistances were found for HEN10 and HEN2. Overall, HEN6 films exhibited the best corrosion behavior among the investigated films. It was noticed that for 24 h of immersion in SBF solution, this film was also a physical barrier to the corrosion process, not only a chemical one.

Heavy-ion irradiation effects of high-entropy A2Ti2O7 pyrochlore with multi-elements at a site

In this work, the irradiation response of A2Ti2O7 (A represents rare earth elements of Gd, Dy, Ho, Er, Yb and Nd) series ceramics were systematically studied under 3 MeV Au2+ ions. The structural changes pre- and post-irradiation were characterized using X-ray diffraction (XRD), grazing incidence X-ray diffraction (GIXRD) and Raman spectroscopy. After heavy ion irradiation, all the samples undergo structural transformations from ordered pyrochlore to disordered fluorite and then to amorphous phase. The sample surface became fully amorphous when exposed to the maximum irradiation dose. The 5RETO high-entropy pyrochlore exhibits the lowest rate of amorphization during the process of structural transformation. The cation radius ratio and mixed entropy are the primary factors influencing amorphization rate. The cation radius ratio shows a strong positive correlation with the amorphization rate, while the mixed entropy demonstrates a weak negative correlation with the amorphization rate. The cation radius ratio can thus serve as a reliable indicator for predicting the radiation resistance of high-entropy pyrochlore ceramics.

In situ cell for grazing-incidence x-ray diffraction on thin films in thermal catalysis.

A cell for synchrotron-based grazing-incidence x-ray diffraction at ambient pressures and moderate temperatures in a controlled gas atmosphere is presented. The cell is suited for the in situ study of thin film samples under catalytically relevant conditions. To some extent, in addition to diffraction, the cell can be simultaneously applied for x-ray reflectometry and fluorescence studies. Different domes enclosing the sample have been studied and selected to ensure minimum contribution to the diffraction patterns. The applicability of the cell is demonstrated using synchrotron radiation by monitoring structural changes of a 3nm Pd thin film upon interaction with gas-phase hydrogen and during acetylene semihydrogenation at 150 °C. The cell allows investigation of very thin films under catalytically relevant conditions.