98%
921
2 minutes
20
The properties of micromechanically exfoliated graphene on different oxide dielectrics--SiO(2), Al(2)O(3), and HfO(2)--are investigated by Raman spectroscopy and AFM measurement. The pristine graphene has stronger adhesion and a higher hole concentration when the dielectric constant of the underlying oxide is higher. It is found that annealing under a high vacuum significantly enhances the adhesion between graphene and the oxides and causes a shift of the Raman G and 2D bands to a higher wavelength. The high vacuum annealing also causes an increase in carrier concentration of up to ten times with a corresponding Fermi level shift of approximately 0.65 eV for graphene on HfO(2). On the other hand, the high vacuum annealing of graphene on SiO(2) induces a biaxial compressive stress as high as 4 GPa on graphene. The results provide understanding on the interaction of graphene and oxides, which is essential for successful realization of graphene-based electronic devices.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1088/0957-4484/21/33/335706 | DOI Listing |
J Phys Chem A
September 2025
Department of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York 14850, United States.
Ionic liquids (ILs) have been gaining increasing focus in a variety of applications including emerging electric-propulsion concepts. A quantitative understanding of how IL ions fragment during high-energy collisions with background gases is therefore essential for interpreting mass spectra, predicting ion lifetimes in plasma and vacuum environments, and designing IL-based technologies. This work uses molecular dynamics (MD) simulations with a reactive force field to numerically model the collision-induced dissociation (CID) of isolated ions (both positive and negative) and ion clusters (2:1 and 1:2 clusters) of the prototypical ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM-BF), colliding with a nitrogen (N) molecule, exploring all possible fragmentation channels arising from the breaking of both ionic and covalent bonds at collision energies ranging from 10 electron volts (eV) to 100 electron volts (eV) in the laboratory frame.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
September 2025
Leiden Insitute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, Netherlands.
In this study, we report the synthesis of single-crystalline h-BN on Ni(111) under ultrahigh vacuum (UHV) conditions using hexamethylborazine (HMB) as a nonclassical precursor. The novel use of HMB facilitates the diffusion of methyl groups into the bulk of Ni(111), playing a critical role in the achievement of high-quality crystalline h-BN layers. The synthesis is performed on a 2 mm-thick Ni(111) single crystal and on a 2-μm-thick Ni(111) thin film on sapphire to evaluate the feasibility of synthesizing h-BN on industrially relevant substrates.
View Article and Find Full Text PDFFront Sports Act Living
August 2025
School of Physical Education, Zhejiang Guangsha Vocational and Technical University of Construction, Dongyang, China.
Introduction: This study examined the impacts of different negative pressure cupping therapies (PCT) on pain relief, functional recovery, and inflammatory regulation in delayed onset muscle soreness (DOMS) after high-intensity exercise, with the aim of clarifying the dose-effect relationship.
Methods: In this study, 55 healthy male participants aged 18-25 were selected and divided into 5 groups: the control group (CTR; = 11) and NPCT groups at different levels (-25 kPa, -35 kPa, -45 kPa, and -55 kPa; = 11 in each group). A high-intensity protocol, which included 6 sets of lunges, squats, and squat jumps, was adopted to induce DOMS in the quadriceps femoris.
ACS Appl Mater Interfaces
September 2025
University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China.
The development of ultrablack coatings with exceptional absorption (>98%) has historically faced significant scientific and engineering challenges, primarily due to limitations in material selection, structural design, and practical durability. Considering the difficulties in practical applications of ultrablack materials with micro/nano structures and the limitations of planar ultrablack coatings in optical performance, we introduce an innovative integration of conventional planar ultrablack coatings with a specifically engineered trilayer antireflection architecture. This hybrid system incorporates a refractive index distribution (1.
View Article and Find Full Text PDFRev Sci Instrum
September 2025
SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
We report on the development of a robust microfluidic nozzle capable of generating replenishing liquid sheet targets with sub-micron thickness at up to kHz repetition rates, a λ/20 surface flatness over areas of at least 100 μm2, and in-vacuum dimensions of 6 × 1.5 mm2. The platform was evaluated for stability under hundreds of 4.
View Article and Find Full Text PDF