The NiTe2nanocrystals anchored on porous graphene films (NiTe2@PG) were fabricated through a sequential process involving vacuum filtration, annealing, and tellurization. Within this structure, the NiTe2nanocrystals formed via the confined growth of NiTe2nanoparticles. The morphology and structure of the NiTe2@PG composite was examined by scanning electron microscopy, transmission electron microscopy, and x-ray diffraction, while the interfacial interaction between NiTe2and graphene was investigated by x-ray photoelectron spectroscopy and Raman spectroscopy. When evaluated as an anode material for lithium-ion batteries, the NiTe2@PG electrode delivered an initial reversible capacity of 875.7 mAh g-1at a current density of 100 mA g-1. Furthermore, it exhibited outstanding long-term cyclability, retaining specific capacities of 243.5 and 135 mAh g-1after 10 000 cycles at high current densities of 2 and 5 A g-1, respectively. This remarkable electrochemical performance was attributed to the unique architecture of NiTe2@PG and the robust covalent bonding at the graphene/NiTe2interface. The porous graphene scaffold serves not only as a conductive substrate for the growth of NiTe2nanocrystals but also facilitates electron transport. Concurrently, its porous network shortened the diffusion path for Li+ions and enhanced electrolyte permeability. Moreover, the formation of C-Te-Ni covalent bonds between graphene and NiTe2played a crucial role in maintaining the structural integrity of the electrode during cycling.

The development of high-performance anode materials is essential to overcome the limitations associated with conventional graphite electrodes in lithium-ion batteries, and perovskite oxides emerge as promising alternatives due to their structural flexibility and defect chemistry. In this work, the potential of LaSrCoFeO3 perovskite (LSCF) thin films as anode materials is investigated, with particular emphasis on the effect of the post-deposition annealing atmosphere. LSCF thin films were deposited by dc magnetron sputtering and then thermal-treated at 600 °C in air and vacuum. The structural, electrical and electrochemical characterizations show that vacuum annealing promotes a more efficient crystallization, leading to larger crystallites (~240 nm), and to reduced oxidation due to the formation of oxygen vacancies. This reduced state significantly reduces electrical conductivity to ~10−5 Ω·cm. When evaluated as a half-cell anode, the vacuum-annealed films exhibit a theoretical specific capacity of 121 mAh·g−1, high reversibility with anodic and cathodic charge ratio Qa/Qc ≈ 1 and a good cyclic stability, with a loss of discharge capacity of less than 10%. Raman spectroscopy experiments confirm that the film structure remains unchanged upon the electrochemical tests, evidencing the stability of the perovskite structure. These results show that the annealing atmosphere is a determining parameter to optimize the electrochemical performance of LSCF thin films, reinforcing their potential as anodes for future lithium-ion batteries.

Abstract In this work, we report on the study on organic-metal hybrid systems, in particular Co-C60
fullerene thin films. This study mainly focused on the investigation of the morphological
and structural evolution of the film surface after various external stimuli designed to
provide energy to the system. For film growth, we adopted an innovative approach,
combining ion-beam sputtering of a pure metal target with thermal evaporation of C60 in
a co-deposition setup. The films underwent a series of treatments to induce modifications.
Laser and ion irradiations were performed using a pulsed laser, a continuous Ar beam, and
a pulsed C beam. In addition, thermal annealing in vacuum was performed to examine the
long-term effects of temperature. The composition of deposited film was investigated using
Ion Beam Analysis, the morphology and the structure, and the effects of treatments on the
films were studied using SEM and TEM microscopies and Raman spectroscopy. Changes
in electrical resistance were also measured to explore potential applications of these films
after treatment.

Ni thick films have a wide range of applications in mechanical areas for anti-corrosion, anti-friction and protection purposes, and are also extensively employed in the chip packaging field. Yet, the deposition of Ni thick films is still faced with many problems in deposition efficiency, dense structure and adhesion to the substrate. RF magnetron sputtering was employed to deposit on polished Ti substrate up to 10.8 µm thick Ni films at a high deposition rate (45 nm/min) in Ar atmosphere plus a small amount of H2. Vacuum annealing was performed at 400 °C for 5 h. To characterize the adhesion via friction and scratch test, different loads were applied on both surfaces of as-sputtered and post-annealed Ni thick films, and results were comparatively analyzed. The films have high purity, compact structure, smooth surface and strong adhesion strength. Post-annealed samples showed better and stable adhesion of Ni thick films to the substrate surface.

Realizing cascade regulation to photocarrier dynamics via heterophase homojunction construction and surface reconstruction for enhanced photoelectrochemical performance.

Impact of vacuum annealing on the multifunctional properties of RF-sputtered ZnO thin films

Fabrication of Ni-P-B4C coating by cold spraying with subsequent vacuum annealing

Control over the structure and oxygen vacancy of the thin film provide powerful means to engineer the structural, electronic, and optical response of transparent conducting oxides. Here, we demonstrate tunability in heteroepitaxial indium tin oxide (ITO) films grown on (100) yttria-stabilized zirconia (YSZ). Post-deposition annealing in vacuum, argon, and oxygen atmospheres induces distinct modifications in morphology, crystallinity, and oxygen vacancies, as quantitatively and qualitatively revealed by comprehensive structural (XRD, SEM/AFM), chemical (XPS), and vibrational (Raman) characterization techniques. These modifications correlate directly with electrical transport and optical properties, including carrier densities ranging from 10 20 –10 21 cm −3 , mobilities up to 65 cm 2 /Vs, resistivities as low as 2.2 × 10 −4 Ωcm, and epsilon-near-zero (ENZ) wavelength tunability across 1.2–2.1 μ m with low-loss permittivity values ( ε 2 =0.33–0.45). An application-oriented figure of merit analysis ( σ / α ) identifies oxygen as the key post-growth parameter where vacuum annealing yields high-conductivity ENZ-active films, argon annealing balances transparency with low-loss ENZ behavior near 2 μ m, and oxygen annealing maximizes near-infrared (NIR) transparency. These findings establish heteroepitaxial ITO/YSZ as a versatile platform for transparent optoelectronics and ENZ photonic applications.

The exploration of MXenes for electronic applicationsis a rapidlygrowing field in materials science. However, most research has focusedon MXene films, with only a limited number of studies addressing thecharacterization of single-flake devices. In this work, we investigatethe electronic and magnetotransport properties of Ti3C2Tx single-flake devices, exploringthe influence of structural defectivity on their transport mechanisms.We show that negative magnetoresistance present at low temperaturesin single flake samples arises from weak localization, which we analyzeto extract the phase coherence length of single-layer and multi-layerflakes. The study of magnetoresistance for this metallic MXene showsthat the material exhibits quantum transport phenomena when intrinsicelectronic behavior dominates. Moreover, by increasing the defectdensity via thermal annealing in ultrahigh vacuum, we uncover andcharacterize the metal-to-disordered metal transition in Ti3C2Tx, shedding light on newproperties and enriching fundamental knowledge about MXenes.

Two-dimensional MXenes have recently emerged as potential candidates for their excellent electrical and mechanical properties. We report the controlled modulation of thermoelectric properties in Ti3C2T x flexible membranes via vacuum annealing. The as-prepared flexible membrane shows the highest electrical conductivity (∼5000 S m-1 at 373 K) and slightly estimated ZT value of 4.4 × 10-3 at 420 K due to preserved surface terminations and intercalated water contents. Notably, annealing at 300 °C enhances the Seebeck coefficient (∼450 µV K-1) and optimizes the power factor (∼105 µW m-1 K-2 at 450 K), whereas high temperature annealing (400 °C) significantly reduced thermoelectric performance due to excessive oxidation and degradation of the membrane. This work highlights that the tunability of MXene films through controlled annealing and surface functional group modification can significantly enhance the performance of thermoelectric materials for room- to mid-temperature range applications. The investigation of MXenes' thermoelectric properties opens new avenues for their use in flexible electronics and wearable devices.

ABSTRACT The redox interactions between transition metal oxides and sulfur‐containing compounds play a key role in catalytic processes and gas sensing technologies. In this study, we investigated the redox dynamics of Co 3 O 4 (111)/Ir(100) model catalysts in response to the adsorption and decomposition of hydrogen sulfide (H 2 S) using synchrotron radiation photoelectron spectroscopy. Upon adsorption at 300 K, H 2 S partially dissociates to form a mixture of SO 3 2− , S 2− , OH − , SH − , and chemisorbed H 2 S. Subsequent annealing in ultrahigh vacuum induces H 2 desorption below 400 K followed by desorption of H 2 S and H 2 O above 400 K. At temperatures exceeding 500 K, S 2− is progressively oxidized to SO 3 2− and subsequently to SO 4 2− . These transformations are accompanied by temperature‐dependent redox processes involving the Co 3 O 4 (111) surface: initial reduction upon formation of SO 3 2− species at 300 K, partial re‐oxidation upon H 2 desorption, and further reduction with H 2 O release. Above 550 K, annealing induces charge redistribution and lattice oxygen migration, leading to a more homogeneous stoichiometry of the Co 3 O 4 (111) film. This phenomenon reduces the redox response to chemical transformations at the surface. The obtained insights into H 2 S–Co 3 O 4 redox interactions provide a foundation for the rational design of cobalt oxide‐based catalytic gas sensors.

Low-resistivity Ohmic contact formation in β-gallium oxide (β-Ga2O3) is crucial for high-efficiency power electronics and deep-ultraviolet (DUV) optoelectronic devices. In this study, we successfully developed a Ti/Mg/Ti multilayered metal stack (20 nm/50 nm/20 nm) as an Ohmic contact to (001) β-Ga2O3. The Mg interlayer, with its low work function relative to Ti and the electron affinity of β-Ga2O3, effectively reduces the Schottky barrier, enabling low contact resistivity. The Ti layers on both sides of the Mg layer act as protective caps, preventing Mg oxidation and improving chemical stability. Ultraviolet photoelectron spectroscopy (UPS) analysis showed that the Ti/Mg/Ti metal stack achieved a stabilized work function of ∼3.94 eV after 400 °C annealing, close to β-Ga2O3's electron affinity, facilitating efficient electron injection. X-ray photoelectron spectroscopy (XPS) confirmed interfacial stability, indicating that the stack protects the reactive Mg layer while compensating for the higher work function of Ti. Moreover, cross-sectional transmission electron microscopy and elemental mapping analysis reveal that the in situ formed interfacial TiOx layer on (001) β-Ga2O3 is relatively thin (2.5 nm) and homogeneous. Importantly, Mg diffusion into Ti layers highly affects the reduction of the effective work function. Transmission electron microscopy and elemental analysis further confirm that Mg diffuses into the Ti layers, leading to the formation of a Ti-Mg alloy. This alloying effect significantly reduces the effective work function of the contact, thereby facilitating electron injection and lowering the contact resistance. Transmission line model (TLM) measurements revealed a contact resistivity of 6.25 × 10-4 Ω·cm2 for the 400 °C annealed Ti/Mg/Ti metal stack, which is significantly lower than that of Ti or Mg alone. Moreover, TLM measurements performed under cryogenic temperatures revealed that the Ti/Mg/Ti contact stack annealed at 400 °C in an argon (Ar) atmosphere exhibits minimal temperature dependence, indicating that carrier transport is predominantly governed by tunneling. A similar tunneling-dominated behavior was also observed for samples annealed in vacuum and nitrogen (N2) atmospheres. In contrast, contacts annealed in air showed a strong temperature dependence, confirming that thermionic emission is the dominant transport mechanism in this case. These electrical observations are fully supported by XPS analysis, which shows significant oxidation of both Mg and Ti for the air-annealed samples, reduced oxidation for N2 and vacuum annealing, and the lowest oxidation level for Ar annealing. The reduced oxidation in inert and oxygen-free environments enhances tunneling, whereas the high oxide formation in air suppresses tunneling and strengthens thermionic emission. Overall, the combined TLM and XPS results clearly demonstrate that the annealing atmosphere plays a critical role in defining the contact transport mechanism, with Ar providing the most stable and tunneling-favorable interface. Finally, the proposed metal stack-based Ohmic contact (Ti/Mg/Ti contact stack annealed at 400 °C in an Ar atmosphere) was incorporated into β-Ga2O3-based metal-semiconductor-metal (MSM) photodetectors to assess device performance. Under 2 μW of 255 nm DUV illumination, the devices exhibited a high responsivity of 14,240.7 A/W. These findings demonstrate that the Ti/Mg/Ti multilayer approach effectively combines low work function engineering with oxidation protection to achieve low-resistance, chemically stable Ohmic contacts. This strategy offers a promising route for enhancing β-Ga2O3-based high-power and DUV optoelectronic devices.

The general procedure for measurement of impurities in hot zones of high-temperature growth setups is proposed and developed. In the first step, we prepared extra-pure 15 × 15 × 8 mm collecting cubes from composite graphite by high-temperature annealing in dry dynamic vacuum. The collecting cubes were placed in different parts of the hot zones of growth setups. We tested two types of crystal growth setups: single- and multi-crucible growth setups of a VGF configuration for AIIIBV semiconductors’ crystal growth. The hot zones of the setups were built from different types of graphite materials and high-temperature dielectric ceramics (BN and Al2O3) as insulators. The growth setups with collecting cubes without raw crystal materials were heated to operating temperatures, exposed for certain operating periods, and cooled to room temperature. The cubes were taken off and analyzed by extraction of condensed impurities into an analytic super-pure acid. The extracted impurities in the acid were determined by ICP-MS analysis. We showed that the hot zone of a single-crucible growth setup was nearly twice as pure (averaged 2.45 mg/g) compared with the hot zone of a multi-crucible setup (averaging 4.06 mg/g) because of the different graphite materials of the constructions.

ABSTRACT The synthesis of graphene at lower temperatures remains challenging, along with the expansion of its application areas. Here we demonstrated the graphene synthesis on various substrates at and above 350°C by a solid phase reaction method. In this method, C‐rich Ni–C films are deposited on the substrates by conventional magnetron sputter deposition at room temperature with a binary target, followed by vacuum annealing. This resulted in phase separation of the multilayer graphene on top. The temperature dependence of graphene formation is investigated by high‐resolution transmission electron microscopy (TEM), in situ X‐ray diffraction (XRD) and Raman spectroscopy. Graphene thus synthesized on a stainless steel (SS) plate is successfully used to enhance the biofilm formation and the current generation by Geobacter species for use in microbial fuel cell application. As transfer‐free graphene can be synthesized directly on substrates irrespective of their material and shape, and is usable in harsh environment of liquid, this simple method is believed to be quite promising for a variety of applications.

Abstract Ultra‐wide bandgap semiconductor gallium oxide (Ga 2 O 3 ) is rising as a promising candidate for the applications in solar‐blind UV detectors, radio frequency devices, and power electronics. However, the randomly distributed oxygen vacancy (V O ) defects result in the disorganized local energy level, limiting the carrier transport and device performance. Here we report the energy level alignment based on the Gradient Passivation of Oxygen Vacancy (GPVO), enabled by the migration of shallower oxygen interstitial defects (O i ) toward Ga 2 O 3 film surface, and the recombination of deeper O i with V O through vacuum annealing. We construct the gradually increased E f of Ga 2 O 3 film along the direction from surface to bulk, and improve the built‐in electric field of Ga 2 O 3 vertical Schottky diode. Therefore, we fabricate the Ga 2 O 3 Solar‐blind UV detectors with enhanced responsivity and specific detectivity of 8.6 A W −1 and 1.5 × 10 15 Jones under 254 nm illumination, at bias voltage of −1.7 V, as well as the shorter response time of 1.04 s/16 ms. Moreover, we report the first 64 × 64 Ga 2 O 3 image sensor and demonstrate the solar‐blind UV video imaging of complex images.

In this study, we fabricated Fe-25Ni-15Cr alloy rods via vacuum induction melting, electroslag remelting, forging, hot rolling, and annealing. We systemically investigated the influence of varying cold-drawing deformation levels (10–60%) on microstructure evolution and mechanical properties, which were characterized by a variety of multi-scale characterization techniques, including optical microscopy, scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The results show that when the cumulative deformation amount is less than 30%, the hardness, tensile strength, and yield strength increase significantly with the increase in deformation amount, while the elongation continues to decline; when the cumulative deformation amount exceeds 30%, the rates of increase in hardness and strength decrease significantly; and when the deformation amount increases to 50%, dislocation density accumulates preferentially at the grain boundaries and forms a cellular substructure, while the texture orientation gradually stabilizes from random distribution to the <111> direction. This alloy rod exhibits three strengthening mechanisms during cold drawing: grain refinement, second-phase precipitation, and work hardening. A predictive model for tensile strength is derived through theoretical calculations. This work has guiding significance for establishing a cold-drawing process window without intermediate annealing.

ABSTRACTVinylidene Fluoride (VDF)‐based polymers are renowned for their remarkable electroactive properties, encompassing the piezoelectric, pyroelectric, and ferroelectric effects. These properties make them highly sought‐after in a wide range of applications, such as sensors and energy storage. The modulation of their dielectric characteristics is intricately linked to the crystalline polymorphism, which is contingent upon specific processing conditions. Herein, we evaluate the potential for enhancing these dielectric functionalities through modifications of the casting conditions (i.e., solvent and evaporation rate). Our findings demonstrate that superior structural characteristics and enhanced dielectric properties are achieved when casting from highly polar solvents followed by a vacuum annealing treatment. This simple and efficient method eliminates the need for extensive and complex processing methods and holds promise for streamlining industrial integration on a larger scale by reducing energy costs related to common integration processes.

Preparation and cyclic oxidation behavior of Pt-modified Ni3Al-based coatings: Effects of Al/Pt content and vacuum annealing time

Ultra-high vacuum annealing treatment for 2D WS2 grown by chemical vapor deposition

Ceria has recently regained attention in catalysis research,thanksto its ability to reversibly form and redisperse supported, catalyticallyactive Pt clusters through control of its surface morphology and oxidationstate. In the present article, we systematically and independentlytune these parameters during CeO2(111) film synthesis toinvestigate their influence on the dimensionality (2D vs 3D) and sinteringbehavior of size-selected Pt20 clusters. We present recipesfor atomically flat CeO2(111) islands and closed filmswith a thickness of up to 18 monolayers, grown on Rh(111), and characterizethem by means of scanning tunneling microscopy (STM), X-ray photoelectronspectroscopy (XPS), X-ray diffraction (XRD), and low-energy electrondiffraction (LEED). Remarkably, XRD and LEED reveal an epitaxiallygrown, crystalline, and relaxed closed film of a single domain, withcube-on-cube alignment. Bulk or exclusive surface reduction is achievedby ultra-high vacuum annealing or room temperature CH3OHdosing and annealing cycles, respectively. The methanol procedureforms oxygen vacancies only in the surface without reducing the deeperlayers of the film or introducing roughening. From STM images, weextract detailed height distributions and coverages of Pt20 clusters and find that Ostwald ripening already sets in around 600K on both, fully oxidized and surface-reduced ceria, without any indicationfor cluster diffusion and coalescence. XPS shows that atom detachmentduring sintering leads to the intermediate formation of Pt2+ species on oxidized ceria, in line with the redispersed single atomsat step edges observed in the literature. Strikingly, while the clustersappear similarly upon deposition on both supports, they show a distincttemperature-dependent dimensionality upon annealing: Exclusively 3Dclusters form on the oxidized support, while most clusters on thereduced support adopt a flat, 2D geometry upon sintering, stabilizedby O vacancies.