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Accurate and efficient measurements of the piezoelectric properties of AlN and AlScN films are very important for the design and simulation of micro-electro-mechanical system (MEMS) sensors and actuator devices. In this study, a process control monitor (PCM) structure compatible with the device manufacturing process is designed to achieve accurate determination of the piezoelectric coefficients of MEMS devices. Double-beam laser interferometry (DBLI) and laser Doppler vibrometry (LDV) measurements are applied and combined with finite element method (FEM) simulations, and values of the piezoelectric parameters d33 and d31 are simultaneously extracted. The accuracy of d31 is verified directly by using a cantilever structure, and the accuracy of d33 is verified by in situ synchrotron radiation X-ray diffraction; the comparisons confirm the viability of the results obtained by the novel combination of LDV, DBLI and FEM techniques in this study.

Deploying energy storage and carbon capture at scale is hindered by the substantial endothermic penalty of decomposing CaCO3 to CaO and CO2, and the rapid loss of CO2 absorption capacity by CaO sorbent particles due to sintering at the high requisite decomposition temperatures. The decomposition reaction mechanism underlying sorbent deactivation remains unclear at the atomic level and nanoscale due to past reliance on postmortem characterization methods with insufficient spatial and temporal resolution. Thus, elucidating the important CaCO3 decomposition reaction pathway requires direct observation by time‐resolved (sub‐)nanoscale methods. Here, chemical and structural dynamics during the decomposition of CaCO3 nanoparticles to nanoporous CaO particles comprising high‐surface‐area CaO nanocrystallites are examined. Comparing in situ transmission electron microscopy (TEM) and synchrotron X‐ray diffraction experiments gives key insights into the dynamics of nanoparticle calcination, involving anisotropic CaCO3 thermal distortion before conversion to thermally dilated energetically stable CaO crystallites. Time‐resolved TEM uncovered a novel CaO formation mechanism involving heterogeneous nucleation at extended CaCO3 defects followed by sweeping reaction front motion across the initial CaCO3 particle. These observations clarify longstanding, yet incomplete, reaction mechanisms and kinetic models lacking accurate information about (sub‐)nanoscale dynamics, while also demonstrating calcination of CaCO3 without sintering through rapid heating and precise temperature control. This work reveals insights into chemical and structural dynamics during the thermal decomposition of CaCO3 nanoparticles to nanoporous high‐surface‐area CaO, whilst avoiding particle sintering. Time‐resolved transmission electron microscopy uncovers a novel CaO formation mechanism and synchrotron X‐ray diffraction reveals anisotropic CaCO3 thermal distortion preceding conversion to energetically stable CaO crystallites. These observations clarify longstanding, yet incomplete, reaction mechanisms about CaCO3 calcination.

As semiconductor interconnects scale toward sub‐2 nm nodes, they are subjected to increasingly high current densities that challenge materials reliability. While phase transformations are traditionally interpreted through thermal equilibrium, electric current can introduce additional nonequilibrium effects that influence structural evolution. Here, we report a current‐driven monoclinic‐to‐hexagonal transformation in Cu6Sn5 occurring under a measured bulk temperature of ∼120°C, below the equilibrium η′ ↔ η transition temperature of 186°C–189°C. Using an ex situ synchrotron X‐ray diffraction series on separate current‐stressed samples together with transmission electron microscopy, we show that matched bulk‐temperature thermal aging alone did not reproduce the same transformation within the examined time window, whereas current stressing progressively converted η′‐Cu6Sn5 to η‐Cu6Sn5. The transformed state also exhibits a higher measured indentation modulus and hardness than the monoclinic reference under the present test conditions. These results demonstrate that electric current can drive unconventional structural evolution in Cu6Sn5 below the equilibrium transition temperature and provide a basis for understanding current‐assisted phase stability in conductive intermetallics. Electric current induces a monoclinic‐to‐hexagonal phase transformation in Cu6Sn5 at a measured bulk temperature of ∼120°C, below the equilibrium transition temperature. Ex situ synchrotron x‐ray diffraction, TEM, and matched thermal controls show that current stressing promotes the formation of a retained hexagonal η‐phase post‐stress state not reproduced by bulk thermal exposure alone.

Variations in the geochemistry and mineralogical compositions of ferromanganese (Fe‐Mn) nodules are closely related to variations in environmental parameters. Therefore, analysis of Fe‐Mn nodules can reconstruct the paleo‐ocean environment. Here, three differently shaped Fe‐Mn nodules were collected from the open seamount 9‐1 of the western Pacific Magellan Seamount. Geochemical and mineralogical analyses were conducted using micro X‐ray fluorescence (μ‐XRF) and Synchrotron X‐ray powder diffraction to reconstruct the paleo‐ocean environment. We found that the shape of the three nodules was different; however, the variations in their geochemical and mineralogical properties were similar. For all three nodules, the μ‐XRF elemental distribution revealed a distinct alternation between the Mn‐rich and Fe‐rich layers. The Mn‐rich and Fe‐rich layers surrounded the nuclei and appeared as concentric circles. Fe‐rich and Mn‐rich layers exhibited low Mn/Fe ratios (<2.5) and were dominated by vernadite, whereas layers with high Mn/Fe ratios (>2.5) were dominated by todorokite, respectively. These findings suggest an early diagenesis process at tabletop of the Magellan Seamount. The high contents of Ca and P and the existence of carbonate fluorapatite in the center of Fe‐Mn nodules indicate that the formation of these nodules began during the Miocene phosphatization event (19–16 Ma). In the early stages of nodule formation, a diagenetic process drove Fe‐Mn nodule formation. Because of global cooling from 9 Ma, early diagenesis was weakened, after which the formation of hydrogenetic Fe‐Mn nodules became dominant. As a result, variations in oxygen minimum zones and oxic‐suboxic fronts were recorded in Fe‐Mn nodules from tabletop of the seamount. Plain Language Summary The geochemistry and mineralogy of ferromanganese nodules (Fe‐Mn nodules) reflect variations in environmental parameters. Three differently shaped Fe‐Mn nodules were collected from the western Pacific Magellan Seamount. Geochemical and mineralogical analyses were performed using micro X‐ray fluorescence and Synchrotron X‐ray powder diffraction to reconstruct the paleo‐ocean environment. The analyses showed that the shape of the three nodules was different, whereas their variations in geochemical and mineralogical properties were similar to each other. The results revealed a distinct alternation between Mn‐rich and Fe‐rich layers in Fe‐Mn nodules. This suggests an early diagenesis process at the western Pacific Magellan Seamount’s tabletop. The existence of carbonate fluorapatite indicates that the formation of these nodules began at the phosphatization event, 19–16 Ma. In the early stages of formation, a diagenetic process formed Fe‐Mn nodules. Due to global cooling from 9 Ma, early diagenesis was weakened, after which the formation of hydrogenetic nodules became dominant. Key Points Fe‐Mn nodules had different appearances but showed similarities in mineralogical and geochemical properties Formation mechanism of Fe‐Mn nodules changed from a diagenetic origin to a hydrogenetic origin during Fe‐Mn nodule formation Early diagenesis affected Fe‐Mn nodule formation at the tabletop of Magellan Seamount

A structural derivative of quartz with the composition Mg0.5AlSiO4 has been grown from glass and characterized using synchrotron X-ray diffraction (XRD), transmission electron microscopy (TEM), and 29Si nuclear magnetic resonance (NMR) spectroscopy. Rietveld analysis of the XRD data indicates that the framework of Mg0.5AlSiO4 is isostructural with α-quartz, rather than β-quartz, as is consistent with previous theoretical modeling (Sternitzke and Muller 1991). Al and Si exhibit long-range disorder over the framework tetrahedral sites, indicated by the absence of the superlattice reflections corresponding to the doubling of c relative to that of quartz. Nevertheless, 29Si NMR measurements show that Al and Si exhibit partial short-range order with an ordering degree of 56%. Electron diffraction reveals superlattice reflections indicative of doubled periodicities along the A: -axes. Fourier electron density maps show that Mg occupies channel sites that each are bonded to six O atoms, in contrast to the tetrahedral coordination of Li in the β-quartz-type framework for β-eucryptite, LiAlSiO4. Furthermore, the concentrations of Mg in adjacent channels are different, resulting in framework distortions that generate the superstructures along A: .

In this paper, we report the results of the first study focused on the thermal stability and dehydration dynamics of the natural zeolite mineral ferrierite. A sample from Monastir, Sardinia [(Na0.56K1.19Mg2.02Ca0.52Sr0.14) (Al6.89Si29.04)O72·17.86H2O; a = 19.2241(3) Å; b = 14.1563(2) Å; c = 7.5106(1) Å, V = 2043.95(7) Å3] was investigated by thermogravimetric analysis and in-situ synchrotron X-ray powder diffraction. Thermogravimetric data show that H2O release begins already in the range 50-100 °C and is complete at ∼600 °C. The results of the structure refinements performed in Immm space group by Rietveld analysis with data collected up to 670 °C show that ferrierite belongs to the group of zeolites that do not undergo phase transitions. Upon heating to 670 °C, ferrierite behaves as a non-collapsible structure displaying only a slight contraction of the unit-cell volume (ΔV = -3%). The unit-cell parameter reductions are anisotropic, more pronounced for a than for b and c (Δa = -1.6%; Δb = -0.76%; Δc = -0.70%). This anisotropic response to a temperature increase is interpreted as due to the presence in the ferrierite framework of five-membered ring chains of SiO4 tetrahedra, which impart a higher structural rigidity along b and c. Upon dehydration we observe: (1) the gradual H2O loss, beginning with the molecules hosted in the 10MR channel, is almost complete at 670 °C, in good agreement with the TG data; (2) as a consequence of the decreased H2O content, Mg and K migrate from their original positions, moving from the center of the 10MR channel toward the walls to coordinate the framework oxygen atoms. The observation of transmission electron microscopy selected-area electron diffraction patterns revealed defective crystals with an occasional and moderate structural disorder. Beyond providing information on the thermal stability and behavior of natural ferrierite, the results of this work have significant implications for possible technological applications. These data allow for comparison with the dehydration kinetics/mechanisms of the corresponding synthetic phases, clarifying the role played by framework and extra-framework species on the high-temperature behavior of porous materials with ferrierite topology. Moreover, the information on the thermal behavior of natural ferrierite can be used to predict the energetic performances of analogous synthetic Si-pure counterparts, namely \"zeosil-electrolyte\" systems, under non-ambient conditions. Specifically, the very high thermal stability of ferrierite determined in this study, coupled with the baric behavior determined in other investigations, suggests that the \"Si-FER-electrolyte\" system may be an excellent candidate for use as an energy reservoir. Indeed, ferrierite exhibits the so-called \"spring behavior,\" i.e., upon compression in water or in an electrolyte solution, it converts the mechanical energy into interfacial energy, and-when pressure is released-it can completely restore the supplied mechanical energy accumulated during the compression step.

In situ synchrotron high‐energy X‐ray powder diffraction (XRD) is highly utilized by researchers to analyze the crystallographic structures of materials in functional devices (e.g. battery materials) or in complex sample environments (e.g. diamond anvil cells or syntheses reactors). An atomic structure of a material can be identified by its diffraction pattern along with a detailed analysis of the Rietveld refinement which yields rich information on the structure and the material, such as crystallite size, microstrain and defects. For in situ experiments, a series of XRD images is usually collected on the same sample under different conditions (e.g. adiabatic conditions) yielding different states of matter, or is simply collected continuously as a function of time to track the change of a sample during a chemical or physical process. In situ experiments are usually performed with area detectors and collect images composed of diffraction patterns. For an ideal powder, the diffraction pattern should be a series of concentric Debye–Scherrer rings with evenly distributed intensities in each ring. For a realistic sample, one may observe different characteristics other than the typical ring pattern, such as textures or preferred orientations and single‐crystal diffraction spots. Textures or preferred orientations usually have several parts of a ring that are more intense than the rest, whereas single‐crystal diffraction spots are localized intense spots owing to diffraction of large crystals, typically >10 µm. In this work, an investigation of machine learning methods is presented for fast and reliable identification and separation of the single‐crystal diffraction spots in XRD images. The exclusion of artifacts during an XRD image integration process allows a precise analysis of the powder diffraction rings of interest. When it is trained with small subsets of highly diverse datasets, the gradient boosting method can consistently produce high‐accuracy results. The method dramatically decreases the amount of time spent identifying and separating single‐crystal diffraction spots in comparison with the conventional method. The capability of machine learning methods for identifying and separating artifacts that appear in a typical X‐ray diffraction image is demonstrated.

The utilization of synchrotron X-ray powder diffraction (SXPD) has allowed us to better understand materials properties on the basis of charge densities and electrostatic potentials as well as atomic configurations in crystals. This article describes capability of SXPD in visualizing materials properties by a revisit to charge density studies and electrostatic potential imaging in manganese oxides, spin crossover complexes, transition metal cyanides, etc. Results obtained in our studies clearly warrant further research on visualization of electrostatic properties taking into account nanostructure analysis by total scattering.

SignificanceThree-dimensional (3D) Dirac semimetals have attracted a lot of advanced research recently on many exotic properties and their association with crystalline and electronic structures under extreme conditions. As one of the fundamental state parameters, high pressure is an effective, clean way to tune lattice as well as electronic states, especially in quantum states, thus their electronic and magnetic properties. In this paper, by combining multiple experimental probes (synchrotron X-ray diffraction, low-temperature transport under magnetic field) and theoretical investigations, we discover the pressure-induced 3D Dirac semimetal to superconductor transition in ZrTe5. As a new type of topological materials, ZrTe5 shows many exotic properties under extreme conditions. Using resistance and ac magnetic susceptibility measurements under high pressure, while the resistance anomaly near 128 K is completely suppressed at 6.2 GPa, a fully superconducting transition emerges. The superconducting transition temperature Tc increases with applied pressure, and reaches a maximum of 4.0 K at 14.6 GPa, followed by a slight drop but remaining almost constant value up to 68.5 GPa. At pressures above 21.2 GPa, a second superconducting phase with the maximum Tc of about 6.0 K appears and coexists with the original one to the maximum pressure studied in this work. In situ high-pressure synchrotron X-ray diffraction and Raman spectroscopy combined with theoretical calculations indicate the observed two-stage superconducting behavior is correlated to the structural phase transition from ambient Cmcm phase to high-pressure C2/m phase around 6 GPa, and to a mixture of two high-pressure phases of C2/m and P-1 above 20 GPa. The combination of structure, transport measurement, and theoretical calculations enable a complete understanding of the emerging exotic properties in 3D topological materials under extreme environments.

Selective laser melting is a promising powder-bed-based additive manufacturing technique for titanium alloys: near net-shaped metallic components can be produced with high resource-efficiency and cost savings [...]