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Here, we report on a study of nickel germanate formation in the Ni(OH)2–GeO2 system under solid‐phase synthesis conditions in the 500–800°C temperature range and on the research of electrochemical performance of Ni2GeO4‐based electrodes. It is shown that the Ni2GeO4 formation occurred at temperatures around 700°C, and the process began with the melting of the nonautonomous phase GeO2 at Tm2n = 725 ± 112°C. The nickel germanate‐based electrodes showed a rapid decrease in capacity over 40 cycles. However, starting from the 80th cycle, a gradual increase in capacity was observed from 190 to 528 mAh/g at the 270th cycle. We attribute this increase in capacity to evolution in the specific surface area and porosity of the electrode material during long‐term cycling. Formation of Ni2GeO4 during solid‐phase reaction is studied in the 500–800°C range. Intense Ni2GeO4 growth occurs around 700°C, and it is related to GeO2 melting. The Ni2GeO4‐based electrodes show a rapid decrease in capacity over 40 cycles. Starting from the 80th cycle, an increase in capacity is observed from 190 to 528 mAh/g at the 270th cycle.

Purpose A solid-state PET/CT system uses bismuth germanium oxide (BGO) scintillating crystals coupled to silicon photomultipliers over an extended 32 cm axial field-of-view (FOV) to provide high spatial resolution and very high sensitivity. Performance characteristics were determined for this digital-BGO system, including NEMA and EARL standards. Methods Spatial resolution, scatter fraction (SF), noise equivalent count rate (NECR), sensitivity, count rate accuracy, and image quality (IQ) were evaluated for the digital-BGO system as per NEMA NU 2-2018, at 2 sites of first clinical install. System energy resolution was measured. Bayesian penalized-likelihood reconstruction (BPL) was used for IQ. EARL Standards 2 studies were reconstructed by BPL combined with a contrast-enhancing deep learning algorithm. An Esser PET phantom was evaluated. Three patient examples were obtained with low-dose radiotracer activity: 2 MBq/kg of [ 18 F]FDG ([ 18 F]-2-fluoro-2-deoxy- d -glucose), 2.3 MBq/kg [ 68 Ga]Ga-DOTA-TATE ([dodecane tetra-acetic acid,Tyr 3 ]-octreotate), and 14.5 MBq/kg [ 82 Rb]RbCl ([ 82 Rb]-rubidium-chloride). Total scan times were ≤ 8 min. Results NEMA sensitivity was 47.6 cps/kBq at the axial center. Spatial resolution at 1 cm from the center axis was ≤4.5 mm (filtered back projection) and ≤3.8 mm (ordered subset expectation maximization). SF was 35.6%, count rate accuracy was 2.16%, and peak NECR was 485.2 kcps at 16.9 kBq/mL. Contrast for IQ was 61.1 to 90.7% (smallest to largest sphere) with background variations from 7.6 to 2.1%, and a “lung” error of 4.7%. The average detector energy resolution was 9.67%. Image quality for patient scans was good. EARL Standards 2 criteria were robustly met and Esser phantom features ≥4.8 mm were resolved at 2 min per bed position. Conclusion A solid-state 32 cm axial FOV digital-BGO PET/CT system provides good spatial and energy resolution, high count rates, and superior NEMA sensitivity in its class, enabling fast clinical acquisitions with low-dose radiotracer activity.

Significance: The highest absorption peaks of the main components of bone are in the mid-infrared region, making Er:YAG and CO2 lasers the most efficient lasers for cutting bone. Yet, studies of deep bone ablation in minimally invasive settings are very limited, as finding suitable materials for coupling high-power laser light with low attenuation beyond 2  μm is not trivial. Aim: The first aim of this study was to compare the performance of different optical fibers in terms of transmitting Er:YAG laser light with a 2.94-μm wavelength at high pulse energy close to 1 J. The second aim was to achieve deep bone ablation using the best-performing fiber, as determined by our experiments. Approach: In our study, various optical fibers with low attenuation (λ  =  2.94  μm) were used to couple the Er:YAG laser. The fibers were made of germanium oxide, sapphire, zirconium fluoride, and hollow-core silica, respectively. We compared the fibers in terms of transmission efficiency, resistance to high Er:YAG laser energy, and bending flexibility. The best-performing fiber was used to achieve deep bone ablation in a minimally invasive setting. To do this, we adapted the optimal settings for free-space deep bone ablation with an Er:YAG laser found in a previous study. Results: Three of the fibers endured energy per pulse as high as 820 mJ at a repetition rate of 10 Hz. The best-performing fiber, made of germanium oxide, provided higher transmission efficiency and greater bending flexibility than the other fibers. With an output energy of 370 mJ per pulse at 10 Hz repetition rate, we reached a cutting depth of 6.82  ±  0.99  mm in sheep bone. Histology image analysis was performed on the bone tissue adjacent to the laser ablation crater; the images did not show any structural damage. Conclusions: The findings suggest that our prototype could be used in future generations of endoscopic devices for minimally invasive laserosteotomy.

Silicon and Germanium oxide (SiOx and GeOx) nanostructures are promising materials for energy storage applications due to their potentially high energy density, large lithiation capacity (~10X carbon), low toxicity, low cost, and high thermal stability. This work reports a unique approach to achieving controlled synthesis of SiOx and GeOx nanostructures via photonic curing. Unlike conventional methods like rapid thermal annealing, quenching during pulsed photonic curing occurs rapidly (sub‐millisecond), allowing the trapping of metastable states to form unique phases and nanostructures. We explored the possible underlying mechanism of photonic curing by incorporating laws of photophysics, photochemistry, and simulated temperature profile of thin film. The results show that photonic curing of spray coated 0.1 M molarity Si and Ge Acetyl Acetate precursor solution, at total fluence 80 J cm−2 can yield GeOx and SiOx nanostructures. The as‐synthesized nanostructures are ester functionalized due to photoinitiated chemical reactions in thin film during photonic curing. Results also showed that nanoparticle size changes from ~48 nm to ~11 nm if overall fluence is increased by increasing the number of pulses. These results are an important contribution towards large‐scale synthesis of the Ge and Si oxide nanostructured materials which is necessary for next‐generation energy storage devices. Silicon oxide (SiOx) and germanium oxide (GeOx) nanoparticles are promising candidates for energy storage applications. We synthesized SiOx and GeOx nanostructures by employing photonic curing; a low‐cost roll‐to‐roll instantaneous process. This work is a step to optimize photonic curing for semiconductor oxide nanostructures synthesis on a large scale with nanometric control for next generation energy applications.

The valence band of photoelectron spectra of complex samples (multicomponent samples, samples with oxide films, molecules adsorbed on the surface) has a complex structure, which complicates the interpretation of the contributions of various sample components to the spectral structure. A method is considered for interpretation of valence band spectra as a result of calculating the density of electronic states for a physical volume using quantum chemistry—an atomic model that most fully characterizes the sample under study. The optimal position of atoms in a given physical volume of the computational model was found using the iterative Broyden–Fletcher–Goldfarb–Shanno (BFGS) numerical optimization method taking into account the spatial distribution of the potential obtained from quantum chemical calculation. The calculation was performed using code written in Python using the ASE and GPAW libraries (atomic simulation environment and grid-based projector-augmented wave) on the equipment of a supercomputer computing cluster. The data obtained by calculation were compared with the measured photoelectron spectra of various systems, such as Ge(111), GeO 2 /Ge(111), C 60 F 18 /Ge(111), and C 60 F 18 /GeO 2 /Ge(111). The analysis made it possible to determine the contributions of various atoms and bonds to the final photoelectron spectrum, estimate the thicknesses of individual layers, and determine the types of bonds between molecules and the substrate.

A simple method for the preparation of doped GeO 2 aerogels is proposed. At the first stage, a gel with a composition of (NH 4 ) 3 H(Ge 7 O 16 )(H 2 O) x was obtained by dissolving germanium dioxide in aqueous ammonia with pH 8.2. The dopant ions were introduced by impregnating the hydrogels with a dimethyl sulfoxide (DMSO) solution of praseodymium nitrate. The optimum conditions of the synthesis were determined, which allow uniform distribution of the dopant ion in the matrix. The Pr/Ge ratio in the resulting aerogels was 0.1. The aerogel samples were characterized in detail by IR, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), low-temperature nitrogen adsorption, etc. It was found that praseodymium affects the luminescence characteristics of GeO 2 aerogels during excitation radiation with a wavelength of 240, 255, and 390 nm.

Germanium/germanium oxide nanoparticles with theoretically high discharge capacities of 1624 and 2152 mAh/g have attracted significant research interest for their potential application as anode materials in Li-ion batteries. However, these materials exhibit poor long-term performance due to the large volume change of 370% during charge/discharge cycles. In the present study, to overcome this shortcoming, a Ge/GeO2/graphene composite material was synthesized. Ge/GeO2 nanoparticles were trapped between matrices of graphene nanosheets to offset the volume expansion effect. Transmission electron microscopy images revealed that the Ge/GeO2 nanoparticles were distributed on the graphene nanosheets. Discharge/charge experiments were performed to evaluate the Li storage properties of the samples. The discharge capacity of the bare Ge/GeO2 nanoparticles in the first discharge cycle was considerably large; however, the value decreased rapidly with successive cycles. Conversely, the present Ge/GeO2/graphene composite exhibited superior cycling stability.

Bismuth germanate glasses doped with cerium oxide were synthesized. The effect of adding cerium oxide on the spectral properties of bismuth-germanate glasses was studied. The Bi2O3 and CeO2 concentration ranges in which the spectral characteristics of these glasses can be adjusted were determined.

In this study, PbO–GeO2 glasses were melt-quenched at different nickel oxide concentrations. XRD and DSC techniques were characterized whether the samples are glass or crystalline materials. IR, Raman, and optical absorption techniques are used to obtain structural details. The IR spectra have revealed that the glass network contained conventional structural units GeO4 and GeO6. The Ni2+ ion octahedral transition exhibited luminescence spectra in the region of 1200–1500 nm; it is due to 3T2 (3F) → 3A2(3F) transition. The glasses containing the highest concentration of NiO have been found to have high values of luminescence efficiency and the cross-section. The dielectric characteristics, such as the dielectric constant, loss, and a.c. conductivity (σac), were analyzed across extensive frequency and temperature ranges, with a specific emphasis on the nickel oxide concentration. Analyzing optical absorption and dielectric properties of the samples, it has been found that nickel ions’ majority occur in tetrahedral sites. It is proved that the dielectric constant and loss values are highest for the sample N10 and ac conductivity due to dipoles being lowest for the sample N10. It is revealed that the glasses are highly conducting due to the modifying action of Ni2+ ions so these glasses are suitable for solid electrolyte uses besides their optical applications in NLO devices.

The new mineral pertoldite was found in a burning waste dump of abandoned Kateřina colliery at Radvanice near Trutnov, Hradec Králové Department, Czech Republic. The dump fire started spontaneously before 1980 and no anthropogenic material was deposited there. The determination of pertoldite as a natural analogue of synthetic trigonal α-GeO2 is based on its chemical composition, X-ray powder diffraction data, and Raman spectroscopy. Pertoldite occurs as white to brownish aggregates resembling cotton tufts, up to 1 mm in size, composed of acicular crystals up to ~1 µm thick and up to 1 mm in length. Individual crystals are distorted, resembling textile fibers. Pertoldite was formed by direct crystallization from hot (400-500 °C) gasses containing Cl and F as transporting agents at a depth of 40-60 cm under the surface of a burning coal mine dump. It nucleated as a thin, delicate crust on a chip of siltstone together with multi-component aggregates of galena, stibnite, bismuthian antimony, greenockite, and bismuth. The ideal formula of pertoldite, GeO2, requires 100 wt. % GeO2. Germanium is partially substituted by silica (2.33-5.67 wt. % SiO2), the extent of Ge1Si-1 substitution is limited to 0.03-0.09 apfu Si, and the empirical formula ranges between (Ge091-0.97Si0.03-0.09)Σ1.00O2. Pertoldite is trigonal, P3121 or P3221, a = 4.980(5) Å, c = 5.644(4) Å, with V = 121.2(2) Å3 and Z = 3. The strongest reflections of the powder X-ray diffraction pattern [d (Å)/I (hkl)] are: 4.315/44(100), 3.425/100(101,011), 2.490/31(110), 2.360/41(012,102), 1.867/31(112), 1.4179/31(023,203), 1.4124/37 (122,212). The crystal structure of pertoldite is based on corner-sharing [GeO4] tetrahedra forming a three-dimensional network similar to that of a-quartz. Pertoldite is named after Zdeněk Pertold (1933-2020), professor of economic geology at the Faculty of Sciences, Charles University in Prague. The mineral and its name have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (number 2021-074) and the holotype specimen is deposited in the collections in the Department of Mineralogy and Petrology, National Museum in Prague, under the catalogue number P1P 31/2021.