Constraints on the time scales of magmatic-hydrothermal processes are key factors in understanding the formation of mineral resources of economic importance that are associated with silicic magmatic systems, including porphyry Cu-Mo-Au systems, Sn-W greisens, and pegmatites. Zircon petrochronology is a widely used tool for determining crystallization ages and temperatures of magmatic systems. In this study, we used the Proterozoic A-type Pikes Peak batholith as a case study to discuss the time scales and chemistry of giant silicic systems, and their relationship with magmatic-hydrothermal mineralized zones. Such mineralizations occur as Nb-Y-F-pegmatites and as mineralized zones in the Redskin granite, a Nb-rich subunit of the Pikes Peak batholith, Colorado. We used zircon petrochronology, feldspar chemistry, and thermodynamic modeling coupled with trace-element modeling via Rayleigh fractionation to understand how the Pikes Peak melt evolved and generated the mineralized zones in the pegmatites and Redskin granite. Our results show that zircon from the main granite is typically magmatic, characterized by bright cathodoluminescence (CL), oscillatory zoning, and low U contents. Pegmatitic zircon grains, in contrast, show high degrees of metamictization, with dark CL and high U contents, indicating crystallization from a highly differentiated magmatic hydrous fluid. Zircon grains from the Redskin granites show bimodal compositions with both low- and high-U zircon grains, marking a transition from magmatic to hydrothermal crystallization. Through isotope dilution−thermal ionization mass spectrometry (ID-TIMS) dating of the Pikes Peak main granite and the late-stage Redskin granite, we obtained high-precision dates that allowed us to constrain the period from the beginning of the magmatic activity in the Pikes Peak batholith to the crystallization of late exsolved fluid phases contributing to pegmatite formation, spanning a temporal interval of at least 15 m.y. for the full lifetime of the system. Although extensive, the observed 15 m.y. duration for this large-sized batholith (>3000 km2) is comparable to other long-lived magmatic systems of similar size.

ABSTRACT Evidence of metamorphism at ultrahigh‐pressure (UHP) conditions is documented by the presence of coesite, diamond and/or majoritic garnet. However, the growth of UHP‐stable phases such as majoritic garnet is often volumetrically low, and overprinting during exhumation can obscure evidence of UHP growth, making it difficult to positively identify UHP rocks. In this study, we selected garnet‐kyanite schists from three microdiamond‐bearing localities within the Rhodope Metamorphic Complex, located in eastern Greece. Samples from Xanthi, Sidironero, and Kimi have similar bulk rock compositions, but the pressure–temperature (P–T) paths differ. Because the major phases record vanishingly little evidence of metamorphism at UHP conditions, we analyzed zircon grains with complex textures to evaluate if zircon preserves a record of UHP metamorphism. Zircon grains from all localities have cores and rims separated by a characteristic interface domain, as revealed by cathodoluminescence (CL) imaging. The detrital igneous cores range in age from c. 2.5 Ga to 220 Ma and exhibit a negative Eu* anomaly, a Yb/Gd of 10–100, and variable Th/U (0–1.2). Rims yield dates of 150–125 Ma with Yb/Gd of 0.1–10 and Th/U of 0–0.2. Interface domains yield dates 165–145 Ma with Yb/Gd ranging between 0–1000 and Th/U < 0.2. We interpret the distinctive CL textures and Yb/Gd of the interface domains as evidence of zircon that reacted at UHP. The interface domain in zircon from all petrographic contexts yields variable Yb/Gd ratios that are significantly higher than both cores and rims. We therefore interpret that zircon recrystallized via interface‐coupled dissolution–reprecipitation reaction; this process preferentially partitioned heavy rare earth elements within the interface domain, which explains the higher Yb/Gd ratios. The rim domains equilibrated with the matrix, producing a relatively homogeneous and low Yb/Gd ratio in these domains. The spatial extent and degree of preservation of interface domains are interpreted as a function of the P–T path and minor variations in bulk composition. Interface domains are best preserved in rocks from Xanthi and Sidironero; in these samples, thin, homogeneous, garnet‐stable rims only partially overprint and crosscut the interface domain. In contrast, rocks from Kimi followed a higher‐temperature trajectory and the zircon grains grew large rim domains that overprinted much of the interface domain and the detrital core. Zircon grains from plagioclase‐rich versus quartz‐rich domains within samples from Sidironero show differences in texture, which indicates that local bulk composition can affect what evidence of UHP metamorphism is preserved. Collectively, these samples provide a new, durable marker of metamorphism in UHP rocks and yield new insight about which factors affect the preservation of UHP textures.

Cathodoluminescence (CL) microscopy offers a promising approach to nanoscale analysis, enabling detection of optical emission from a sample while leveraging the high resolution of electron microscopy. However, achieving multicolor single-particle CL imaging remains a significant challenge. Here, using lanthanide nanoparticles as a model system, we identify a critical limitation in CL imaging: nonlocal signal caused by stray electrons. We mitigate these nonlocal excitations and demonstrate multicolor single-particle CL imaging of nanoparticles down to 12 nm in diameter. Using this enhanced sensitivity, we demonstrate that CL brightness increases monotonically with nanoparticle diameter. We propose that multicolor imaging of spectrally distinct nanoparticles in the same field of view, coupled with the scaling of CL brightness with nanoparticle size, is crucial for confirming single-particle CL detection. Finally, we demonstrate the utility of our findings by imaging lanthanide nanoparticles in a biological sample. This work advances our understanding of nanoscale photonic responses to free electrons, establishing CL as a useful contrast mechanism for high-resolution, multicolor electron microscopy.

The precise characterization of bulk properties of thin homoepitaxial diamond layers with micrometer thickness is difficult due to the interference from the substrate. In this work, we utilized smart-cut method to fabricate single-crystal diamond (SCD) cantilevers or plates and transferred them to a foreign substrate (SiO2/Si). The mechanical resonance of the SCD cantilevers was characterized to confirm that the ion-implantation-induced damaged layer was nearly removed under the cantilever. Raman, photoluminescence (PL), and cathodoluminescence (CL) measurements were conducted on the transferred SCD cantilevers/plates and homoepitaxial layers on the substrate with and without ion implantation. As a result, it was found that both of the Raman spectral properties of the SCD layer on the ion-implanted regions and the freestanding SCD plates/cantilevers successfully avoid interference from the substrate. PL analysis showed no emission peaks attributable to nitrogen and other defects from the epilayers. Additionally, CL analysis from the freestanding cantilevers/plates disclosed the exciton emission at around 236 nm at room temperature. These results suggest the high crystal quality of the SCD cantilevers for MEMS applications.

Lead halide perovskites have emerged as promising materials for optoelectronic applications due to their exceptional properties. In the all-inorganic CsPbBr3 perovskites, ferroelastic domains formed during phase transitions enhance bulk transport and emissive efficiency. However, the microscopic mechanisms governing carrier dynamics remain poorly understood. In this study, we employ cathodoluminescence (CL) and micro-Raman spectroscopy to image and investigate the electronic properties of the ferroelastic domain walls in CsPbBr3 single crystals. CL measurements reveal a reduced emissive yield and a slight redshift in emission at the domain walls. Further, micro-Raman studies provide spatially resolved mapping of vibrational modes, exhibiting second-order phonon modes localized at the domain boundaries. Our findings suggest that electron-phonon coupling at the twin domain walls plays a critical role in facilitating efficient charge separation, thereby improving the optoelectronic performance of the CsPbBr3 perovskites.

Surface plasmon polaritons (SPPs) can be manipulated to localize and guide light in subwavelength distances, enabling them to find applications in a wide range of areas, from sensing to quantum computing. Among several methods of SPP excitation, periodic arrays of nano- and microstructures are of particular interest, as they enable engineering SPP properties through structural parameters. Here, using the photon-induced near-field electron microscopy (PINEM) technique, we investigated the mode formation, coupling, interference, and decay of SPPs in square and hexagonal arrays of circular nanoholes under both visible and near-infrared excitation. Polarization-resolved analysis revealed the key factors governing SPP localization and interference patterns, showing that the periodicity and symmetry of the array primarily determine the SPP interference patterns and their orientation, while pump polarization mainly modulates their intensity. Time-resolved PINEM measurements demonstrated the spatial dependence of the SPP temporal characteristics. In addition, cathodoluminescence (CL) spectroscopy was employed to examine the intrinsic plasmonic characteristics of the structure. Finite difference time domain (FDTD) simulations showed strong agreement with both PINEM and CL measurements on the spatial and spectral behavior of SPPs. Understanding the spatiotemporal dynamics of SPPs on nanostructures beyond the diffraction limit is crucial for optimizing plasmonic structures for advanced photonic and quantum technologies.

High-energy electron beams with energies in the 15–30keVrange are used to excite optical Mie modes in crystalline Si nanosphereswith radius 80–100 nm. Cathodoluminescence (CL) spectra showemission from resonant electric and magnetic dipole and quadrupolemodes, with relative intensities that depend strongly on electronenergy and impact parameter. The measured trends are explained bya coupling model in which the electron-energy dependent CL excitationprobability–and thus the CL emission–is proportionalto the Fourier transform of the modal electric field at a spatialfrequency determined by the electron velocity. As a result, the couplingto a specific resonant mode is strongly dependent on the electronenergy and the impact parameter of the electron beam. This enablesthe selective enhancement of CL emission from a resonant mode by phase-matchingwith the electron velocity. A systematic study of spatial excitationprobability for the electric dipole mode as a function of electronenergy further confirms the validity of the coupling model. Angle-resolvedcathodoluminescence measurements show strong directional emissiondue to far-field interference of coherently excited Mie modes. Byvarying the electron energy and impact parameter the intensity andinterference of these modes can be controlled and the angular distributiontailored. The insights in the localized deep-subwavelength coherentexcitation of resonant Mie modes explored here are important for studiesin light-emitting nanostructures, sensors, and photovoltaics, in whichthe interplay of local modes and far-field directional emission mustbe controlled.

The Carboniferous–Permian tight sandstone gas reservoirs in the Shenfu area of the Ordos Basin in China are characterized by the widespread development of multiple formations. However, significant differences exist among the tight sandstones of different formations, and their formation mechanisms and key controlling factors remain unclear, hindering the effective selection and development of favorable tight gas intervals in the study area. Through comprehensive analysis of casting thin section (CTS), scanning electron microscopy (SEM), cathodoluminescence (CL), X-ray diffraction (XRD), particle size and sorting, porosity and permeability data from Upper Paleozoic tight sandstone samples, combined with insights into depositional environments, burial history, and chemical reaction processes, this study clarifies the characteristics of tight sandstone reservoirs, reveals the key controlling factors of reservoir quality, confirms the differential evolutionary mechanisms of tight sandstone of different formations, reconstructs the diagenetic sequence, and constructs an evolution model of reservoir minerals and porosity. The research results indicate depositional processes laid the foundation for the original reservoir properties. Sandstones deposited in tidal flat and deltaic environments exhibit superior initial reservoir qualities. Compaction is a critical factor leading to the decline in reservoir quality across all formations. However, rigid particles such as quartz can partially mitigate the pore reduction caused by compaction. Early diagenetic carbonate cementation reduces reservoir quality by occupying primary pores and hindering the generation of secondary porosity induced by acidic fluids, while later-formed carbonate further densifies the sandstone by filling secondary intragranular pores. Clay mineral cements diminish reservoir porosity and permeability by filling intergranular and intragranular pores. The Shanxi and Taiyuan Formations display relatively poorer reservoir quality due to intense illitization. Overall, the reservoir quality of Benxi Formation is the best, followed by Xiashihezi Formation, with the Taiyuan and Shanxi Formations exhibiting comparatively lower qualities.

To be used as efficient alpha particle scintillator in the fields of nuclear security, nuclear nonproliferation and high-energy physics, scintillator screens must have high light output and fast decay properties. While there has been a great deal of progress in scintillation efficiency, achieving fast decay time properties are still a challenge. In this work, the near band edge (NBE) UV luminescence and alpha particle induced scintillation properties of vertically aligned densely packed ZnO nanorods (NRs) doped with Al, Ga, and In have been thoroughly investigated. The high crystalline hexagonal wurtzite structure with a strong orientation through the c-axis plane (002) and aspect ratios in the range 13–22 have been observed for all ZnO NRs. Electron paramagnetic resonance (EPR) analysis exhibited paramagnetic signals at g ≈ 1.96 for all ZnO NRs. A cost effective green hydrothermal synthesis technique was employed to grow well-aligned NRs. Using citrate as an additive acting as a strong reducing agent in the solution during the crystal growth, defects on the surface are significantly suppressed, thereby enhancing the NBE UV emission. Significantly higher NBE UV emission was observed from the top surface of ZnO NRs in cathodoluminescence (CL) microscopy. Results show that citrate assisted donor doping of ZnO NRs not only reduces the defect emission and NBE self-absorption, but also induces fast decay time (~ 600–700 ps), which makes ZnO NRs a good candidate for fast alpha particle scintillator screens used in associated particle imaging for time and direction tagging of individual neutrons generated in D–T and D–D neutron generators.

Abstract Microbialites have long been utilised by geologists as palaeoenvironmental indicators, despite outstanding questions regarding their formation and preservation in the rock record. Here, we leverage cathodoluminescence (CL) microscopy, a technique commonly used to investigate carbonate formation and diagenetic alteration, to better understand the textural characteristics, formation mechanisms and diagenetic histories of microbialites. We compare CL features to gain insight into palaeoredox conditions and alteration histories for a suite of six microbialite samples spanning from the Proterozoic to modern, finding a strong degree of similarity amongst samples regardless of age or depositional environment. CL reveals that microbialites typically have complex microfabrics that include other accessory minerals and grains, all of which provide insight into their unique formation and palaeoredox histories. We find that the modern microbialite sample showed the greatest difference in CL characteristics compared to the other microbialite samples, most probably because of its aragonitic composition and incomplete lithification. In contrast, the ancient microbialite samples preserve a distinct and most probably primary, mottled luminescence texture despite spanning more than 500 Myr; this mottled texture may typify ancient microbialite fabrics that formed in shallow water settings. We also distinguish a variety of CL characteristics that support previously proposed formation and/or diagenetic histories in these samples. Lastly, we use energy‐dispersive X‐ray spectroscopy to compositionally identify rare grains observed with CL, highlighting the utility of CL as a possible screening tool for both geological and non‐geological components within samples. Our analyses demonstrate the power of using classic CL techniques to answer modern questions in microbialite research.

Cathodoluminescence (CL) microscopy has emerged as a powerful tool for investigating the optical properties of materials at the nanoscale, offering unique insights into the behavior of photonic and plasmonic materials under electron excitation. We introduce an atlas of bulk CL spectra and intensity for a broad range of materials used in photonics and plasmonics. Through a combination of experimental CL microscopy and Monte Carlo simulations, we characterize spectra and intensity of coherent and incoherent CL, electron penetration depth and energy deposition, offering a foundational reference for interpreting CL signals and understanding material behavior under electron excitation. Our atlas captures CL signals across a wide range of materials, offering valuable insight into intrinsic emission properties for informed material selection and device design in photonics and plasmonics.

The pore-throat structure of the extremely low-permeability sandstone reservoir in the Huachi area of the Ordos Basin is complex and highly heterogeneous. Currently, there are issues such as unclear understanding of the micro-pore-throat structural characteristics, primary controlling factors of reservoir quality, and classification boundaries of the reservoir in the study area, which seriously restricts the exploration and development effectiveness of the reservoir in this region. It is necessary to use a combination of various analytical techniques to comprehensively characterize the pore-throat structure and establish reservoir classification evaluation standards in order to better understand the reservoir. This study employs a suite of analytical and testing techniques, including cast thin sections (CTS), scanning electron microscopy (SEM), cathodoluminescence (CL), X-ray diffraction (XRD), as well as high-pressure mercury injection (HPMI) and constant-rate mercury injection (CRMI), and applies fractal theory for analysis. The research findings indicate that the extremely low-permeability sandstone reservoir of the Chang 3 section primarily consists of arkose and a minor amount of lithic arkose. The types of pore-throat are diverse, with intergranular pores, feldspar dissolution pores, and clay interstitial pores and microcracks being the most prevalent. The throat types are predominantly sheet-type, followed by pore shrinkage-type and tubular throats. The pore-throat network of low-permeability sandstone is primarily composed of nanopores (pore-throat radius r < 0.01 μm), micropores (0.01 < r < 0.1 μm), mesopores (0.1 < r < 1.0 μm), and macropores (r > 1.0 μm). The complexity of the reservoir pore-throat structure was quantitatively characterized by fractal theory. Nanopores do not exhibit ideal fractal characteristics. By splicing high-pressure mercury injection and constant-rate mercury injection at a pore-throat radius of 0.12 μm, a more detailed characterization of the full pore-throat size distribution can be achieved. The average fractal dimensions for micropores (Dh2), mesopores (Dc3), and macropores (Dc4) are 2.43, 2.75, and 2.95, respectively. This indicates that the larger the pore-throat size, the rougher the surface, and the more complex the structure. The degree of development and surface roughness of large pores significantly influence the heterogeneity and permeability of the reservoir in the study area. Dh2, Dc3, and Dc4 are primarily controlled by a combination of pore-throat structural parameters, sedimentary processes, and diagenetic processes. Underwater diversion channels and dissolution are key factors in the formation of effective storage space. Based on sedimentary processes, reservoir space types, pore-throat structural parameters, and the characteristics of mercury injection curves, the study area is divided into three categories. This classification provides a theoretical basis for predicting sweet spots in oil and gas exploration within the study area.

In recent years, fast electrons have emerged as ideal probes for exploring the optical properties of nanoscale matter with sub-meV energy resolution and atomic-scale spatial resolution. Considering the remarkable progress in cathodoluminescence (CL) and electron energy-loss spectroscopy (EELS), robust theoretical tools are needed to interpret the plethora of experimental data and provide insight into the properties of matter and its interaction with fast electrons. This tutorial offers a comprehensive overview of analytical methods for simulating CL and EEL spectra of spherical nanoparticles and planar slabs composed of arbitrary isotropic materials. We demonstrate the applicability of these methods to analyze the optical modes sustained in metallic and dielectric nanocavities and explore the underlying physical mechanisms driving the optical response of these systems.

The formation of hydrothermal gold deposits commonly involves complex fluid-fluid and fluid-rock interaction processes. Here, we investigated the micro-texture and in situ trace elemental and oxygen isotopic composition of different quartz from the Zhaoxian gold deposit, Jiaodong, North China, aiming to constrain the evolution and origin of ore-forming fluids under the complex hydrothermal process. Crosscutting relationships and cathodoluminescence (CL) zoning reveal four discrete quartz generations (Qtz-1 to Qtz-4) corresponding to four distinct vein-filling stages (V1−V4) in the hydrothermal system. The CL lightness of quartz shows a positive correlation with Al content but no relationship with δ18O values, suggesting different controls on trace element incorporation versus oxygen isotope fractionation. The elevated content of trace elements in hydrothermal quartz (such as Al, up to 916 ppm in Qtz-2) is ascribed to water-rock interaction, which increased lithophile-element availability. The seism-induced fluid fluctuation enhanced quartz compositional variability via influencing chemical composition and pH value of hydrothermal fluids. The four quartz generations exhibit distinct δ18O values: Qtz-1 (11.35‰−11.63‰), Qtz-2 (12.46‰−15.07‰), Qtz-3 (12.68‰−14.56‰), and Qtz-4 (13.03‰−14.47‰). Calculated δ18O values of corresponding fluids are 4.46‰−4.74‰, 4.20‰−6.96‰, 2.63‰−4.25‰, and −2.46‰ to −1.02‰ for stage I to stage IV, respectively. The O isotopic compositions of ore-forming fluids were negatively shifted by water-rock reaction. Meanwhile, the nearly constant δ18O values at the mineral scale indicate persistent isotopic compositions of pore fluids due to rock buffering, despite fluid fluctuations. The hydrothermal fluids were initially mantle-derived (δ18O ≥7‰) with incorporation of meteoric water in the post-ore stage. The textural and geochemical signatures of quartz serve as effective tracers for constraining water-rock interaction intensities and fluid fluctuations in hydrothermal gold mineralization systems.

This work aimed to synthesize and characterize CeO2:Eu2O3 ceramic powders with molar concentrations (Ce:Eu = 100:0, 98:2, 95:5, 92:8, 90:10, and 70:30). The gels were heat treated at 700 °C for 24 hours to induce crystallization of the ceramic powders. The materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), spectroscopy infrared spectroscopy (IR), Raman spectroscopy, scanning electron microscopy (SEM), photoluminescence (PL), and cathodoluminescence (CL). The results reveal that all ceramic powders presented a cubic (fluorite) structure with modifications in the lattice parameters as the Eu3+ concentrations changed. Furthermore, the Eu2O3 diffraction pattern allowed the complete identification of the crystal planes. The crystallite sizes were 64, 22, 30, 38, 40, and 50 nm for the Ce:Eu3+ ceramic powders at 100:0, 98:2, 95:5, 92:8, 90:10, and 70:30, respectively. XPS results showed a Ce3+/Ce4+ ratio of 0.27%. The IR spectrograms show the M-O bands attributable to CeO2 at 460, 560, 860, and 1200 cm-1. The results of the Raman spectra show three main bands at 260, 468, and 600 cm-1, which are associated with the F2g vibration mode of octahedral local symmetry found around the CeO2 lattice and the defect-induced mode related to the presence of oxygen vacancies due to the existence of Ce4+ ions. The particles exhibited morphological changes due to the change from the doped phase to the solid solution. The higher the concentration of Eu3+, the greater its agglomeration and size. The ceramic powders showed luminescent properties exhibiting emissions mainly by the 5D0-7D2 transition of Eu3+ and the 30 mol% sample showed higher luminescent intensity in cathodoluminescence.

The luminescence characteristics and the relation between the distribution of impurities and stacking faults (SFs) in Mg-doped zincblende gallium nitride (zb-GaN:Mg) have been investigated by cathodoluminescence (CL) and atom probe tomography (APT). Four peaks have been identified in the CL emission spectrum, and the possible related recombination mechanisms have been proposed. The main peak at 3.23 eV is associated with excitonic transitions, while the other three, having lower energies at about 3.15, 3.02, and 2.92 eV, respectively, are related to donor-to-acceptor (DAP) transitions involving different acceptor energy levels. These DAP peaks were significantly more intense on or close to SFs compared to the surrounding defect-free material, indicating an enrichment of point defects near SFs. This finding was supported by APT measurements, where Mg showed a tendency to segregate toward SFs in zb-GaN.

Abstract Due to the enhanced chiral light‐matter interactions along the propagation direction of circularly polarized light, 3D chiral plasmonic nanostructures have shown exceptional chiroptic response for chiral sensing and luminescence. However, the lack of proper design and fabrication strategy causes great difficulties for achromatic chiroptic response with a high g‐factor in the visible region. Here a facile generation of 3D spiral plasmonic micropillars based on laser direct writing with a spiral vector beam is introduced. These plasmonic micropillars exhibit a dissymmetric factor (g‐factor) up to 1.0 at 800 nm, which gives rise to strong chiral plasmon photoluminescence (PL) with an achromatic luminescence dissymmetry (g lum ) up to 0.4 across the visible region (500–750 nm). Furthermore, cathodoluminescence (CL) characterizations of these spiral micropillars reveal a location‐selective chiral inversion of the CL spectra, which is related to the variation of the superchiral fields within the spiral micropillars. This work not only establishes a facile, efficient and enantioselective paradigm for the optical generation of 3D chiral plasmonic nanostructures but also reveals the crucial role of superchiral field in both the chiral PL and CL, which is significant for the development of superior chiral luminescence devices.

ABSTRACT Albitization is a widely recognized aspect of sandstone burial diagenesis, but its temperature of occurrence has been only partly constrained by previous studies. Temperatures of albitization of plagioclase in sandstone samples of Devonian to Miocene age from the Norwegian continental shelf were therefore studied by combining thin-section petrography with temperature measurements from wells. The investigated samples cover burial depths of 504–5120 m and a temperature range of 23–183°C. Albite grains with a morphology indicative of a diagenetic origin are present at temperatures of 88°C and higher, whereas calcic plagioclase was found solely at temperatures below 88°C. Oil inclusions in albitized plagioclase are with one exception present only at temperatures above 87°C. Moreover, albitized grains with a characteristic brown cathodoluminescence (CL) color that differentiates them from detrital albite with red and yellow CL colors are in all but one of the wells examined with CL confined to samples where temperatures exceed 88°C. The non-albitized grains of calcic plagioclase show a variety of CL colors; pink, pale green, yellow to orange, and pale brown, and these CL colors are seen only at temperatures less than 88°C. The data therefore suggest that albitization has in practically all cases taken place around 88°C, and that the reaction is rapid on a geological time scale. These results have several useful applications. Fixing the temperature of albitization constrains sandstone provenance and magnitude of uplift because albitization in a sandstone located at the surface or at shallow depth indicates uplift from depths where temperature was at least 88°C, and in situ albitized plagioclase suggests that the sandstone is not sourced solely from older sandstones once buried to temperatures in excess of 88°C, because such a sand source would not provide reactive plagioclase. Many of the examined reservoirs are presently filled with oil or wet gas, and most of these hydrocarbon-filled reservoirs contain oil inclusions within albitized plagioclase, indicating oil emplacement at temperatures less than 88°C.

In this study, tridymite mineral from Lanzarote, Canary Islands, was investigated using spectroscopic and luminescence techniques for potential applications in dosimetry (e.g., radiation detectors), dating (e.g., through luminescence techniques), and ceramics (as a high-temperature-resistant material). Raman scattering identified molecular vibrations at 155, 220, 320, 370, 410, 445, 800, and 1100 cm-1. The 29Si MAS NMR spectra exhibited a broad signal (75-150 ppm) indicating variations in the silicon environment, supported by environmental scanning electron microscopy-energy dispersive X-ray spectroscopy (ESEM-EDS). Electron paramagnetic resonance (EPR) revealed an unpaired electron in a silicon sp3 orbital (g = 2.0027), increasing with power, suggesting an oxygen vacancy. The blue cathodoluminescence (CL) band suggested oxygen-defect centers (ODCs), with emissions at 400 and 445 nm could be linked to self-trapped excitons (STE) from an oxygen Frenkel pair (Si-O-O-Si) and oxygen vacancies. Emission at 480 nm could be attributed to impurity defects such as GeO₄3- + e and AlO₄4- + e. CL data analysis provided insight into how these defects influence radiative recombination, affecting photoluminescence (PL) emissions at 693 and 694.5 nm. ODCs notably contributed to PL emissions, as evidenced by the 452.5-nm CL peak associated with oxygen vacancies. This study offers valuable insights into tridymite's crystal structure, elemental configuration, molecular dynamics, and luminescent properties.

Abstract Electron beam excitation assisted (EXA) optical microscopy has been developed to establish label-free imaging with sub-diffraction limit resolution under ambient atmosphere. To improve the performance of the EXA microscope, a Gd3+-doped YAlO3 luminescent thin film was fabricated on a LaAlO3 layer. The existence of the LaAlO3 layer enhanced the intensity of cathodoluminescence (CL) of the 4f-4f transition in Gd3+ ions by an order of magnitude as well as inducing a broad emission related to oxygen vacancies. The improvement of the crystallinity of the YAlO3 matrix increased the CL intensity. We demonstrated the possibility of YAlO3:Gd3+/LaAlO3 luminescent thin film as an improved optical probe for EXA microscopy.