Conductive‐bridge random access memory (CBRAM) is considered a strong contender of the next‐generation nonvolatile memory technology. Resistive switching (RS) behavior in CBRAM is decided by the formation/dissolution of nanoscale conductive filament (CF) inside RS layer based on the cation injection from active electrode and their electrochemical reactions. Remarkably, RS is actually a localized behavior, however, cation injects from the whole area of active electrode into RS layer supplying excessive cation beyond the requirement of CF formation, leading to deterioration of device uniformity and reliability. Here, an effective method is proposed to localize cation injection into RS layer through the nanohole of inserted ion barrier between active electrode and RS layer. Taking an impermeable monolayer graphene as ion barrier, conductive atomic force microscopy results directly confirm that CF formation is confined through the nanohole of graphene due to the localized cation injection. Compared with the typical Cu/HfO2/Pt CBRAM device, the novel Cu/nanohole‐graphene/HfO2/Pt device shows improvement of uniformity, endurance, and retention characteristics, because the cation injection is limited by the nanohole graphene. Scaling the nanohole of ion barrier down to several nanometers, the single‐CF‐based CBRAM device with high performance is expected to achieve by confining the cation injection at the atomic scale.

Mercuric ion (Hg2+) is one of the most toxic and serious environment polluting heavy metal ions, which can be accumulated in human body through food chains and drinking water, and causes serious damage to human organs. Therefore, development of the efficient and sensitive method for detection of Hg2+ is very necessary. In this study, the high surface sensitivity and fingerprint information about the chemical structures based on surface‐enhanced Raman scattering (SERS) for sensing applications are taken advantage of. Au triangular nanoarrays/n‐layer graphene/Au nanoparticles sandwich structure with large‐area uniform subnanometer gaps are fabricated and used to detect Hg2+ in water via thymine–Hg2+–thymine coordination; the detection limit of Hg2+ is as low as 8.3 × 10−9m. Moreover, this SERS substrate is used to detect the Hg2+‐contaminated sandy soil and shows excellent performance. This study indicates the sandwich structure has a great potential in detection of toxic metal ions and environmental pollutants.

properties because of their special struc ture. When the materials reach a nano meter size, the electrical, optical, magnetic, and other properties of the materials will be altered greatly because of the small size effect, quantum size effect, sur face and boundary effects, and Coulomb blockade effect. [1] Currently, nanomaterials have been widely applied in many fields, including computers, catalysis, sensors, energy, and environmental protection. [2][3][4][5][6][7][8][9][10][11] As the demand increases, people aspire to fabricate nanomaterials with greater prop erties. Many methods have been used to improve the properties of nanomaterials, including doping, surface reconstruc tion, semiconductor composite, and metal nanoparticle embedding. [12][13][14][15][16][17][18][19][20] These days, ion beam techniques, including ion implantation, irradiation, and focused ion beam (FIB), have been extensively used to modulate the properties of nanomaterials. Moreover, ion beam techniques are regarded as a promising technique for doping and surface modification. Compared with doping during growth and diffusion, ion implantation is more controllable and reproducible. In addition, ion implantation is also an effective method for embedding nanoclusters in body materials. Moreover, ion irradiation is an effective method to modulate the morphology and surface structure of the mate rials. Therefore, via using this technique, various properties of nanomaterials can be tailored. FIB is typically used for the in situ study of ionirradiated materials. Figure 1 shows the applications of ion beam techniques for nanomaterial surface modification.Ion implantation, as an ion beam technique, has been extensively applied to the modulation of nanomaterial sur faces. Moreover, the technique has also been extensively used in the field of microelectronics. Ion implantation has replaced diffusion as a doping method to introduce dopants into the semiconductors. As an industrial technique, it exhibits high controllability and accuracy. In contrast to other doping strat egies, almost all elements can be introduced into the target materials by ion implantation and it does not introduce other impurity elements. In addition, ion implantation is not restricted by the solid solubility of elements in the mate rials. Ion implantation can be described as a collision process Nanomaterials have gained plenty of research interest because of their excellent performance, which is derived from their small size and special structure. In practical applications, to acquire nanomaterials with high performance, many methods have been used to modulate the structure and components of materials. To date, ion beam techniques have extensively been applied for modulating the performance of various nanomaterials. Energetic ion beams can modulate the surface morphology and chemical components of nanomaterials. In addition, ion beam techniques have also been used to fabricate nanomaterials, including 2D materials, nanoparticles, and nanowires. Compared with conventional metho...

Tungsten-graphene multilayer composites are fabricated using a stacking method. The thermal resistance induced by the graphene interlayer is moderate. An ion-implantation method is used to verify the radiation tolerance. The results show that graphene inserted among tungsten films plays a dominant role in reducing radiation damage. Furthermore, the performance of different tungsten period-thicknesses in radiation tolerance is systematically analyzed.