Electrical properties of textured carbon film formed by pulsed laser annealing

Previous works have showed that textured carbon film can be fabricated by applying suitable ion energy and substrate temperature. In this experiment, the effect of laser annealing on amorphous carbon films was studied. Atomic force microscopy shows the effect of laser irradiation on surface morphology of carbon film, and visible Raman spectroscopy shows that the G peak position shifted from 1540 cm− 1 to 1600 cm− 1, and the increase in I(D)/I(G) intensity ratio indicates the formation of more graphitic film at higher laser energy. High resolution transmission electron microscopy (HRTEM) shows the vertical alignment formation at suitable laser energy. Electrical measurement shows that the vertical aligned carbon films exhibit low resistance, ohmic current–voltage characteristics, which suggests that vertical aligned films formed by laser irradiation may be promising material for future nano-device interconnects

The effect of bonding structure of diamond like carbon (DLC) film with surface nickel coating upon laser annealing

Previous work has shown that the bonding structure and phase of amorphous carbon (a-C) can be modified by laser annealing. In this work, the effect of surface modification by metal coating on a-C during laser annealing was studied. A-C film was deposited by the filtered cathodic vacuum arc (FCVA) technique onto n-type (100) silicon substrate at room temperature. Nickel (Ni) was deposited on the surface of a-C films by electron beam (e-beam) evaporation method, and laser annealing with different laser energy density was performed on the a-C films with and without Ni coating. Visible Raman spectroscopy was used to examine the bonding structure evolution upon laser annealing and the effect on the bonding structure of a-C by introducing Ni onto the DLC film surface. The Raman spectra shows more pronounced change for a-C films with Ni coating than those without Ni coating upon laser annealing, and the Raman features also suggest that the Ni surface coating can enhance formation of the six-ring graphitic-like sp2 ordering. Electrical measurement shows a low resistive characteristic for both set of films due to laser induced conducting sp2 clusters formation.Economic Development Board (EDB)Published versionThe authors would like to acknowledge the financial support from GLOBALFOUNDRIES Singapore Pte.Ltd—EDB scholarship scheme

Effect of initial sp3 content on bonding structure evolution of amorphous carbon upon pulsed laser annealing

Previous work has shown that pulsed laser annealing can be used to change the bonding structure of amorphous carbon films. In this paper, the effect of initial sp3 content on bonding structure of amorphous carbon upon pulsed laser annealing was studied. Visible Raman spectroscopy was used to examine the bonding structure evolution. Here we show a detailed analysis of the Raman features—G peak position and I(D)/I(G) ratio of carbon film with initial sp3 content of 80%, 65% and 50%. The laser energy level required to induce the change of the bonding structure of carbon film decreases with the decreasing sp3 content. High resolution transmission electron microscopy (HRTEM) shows the formation of graphitic sp2 clusters form at proper laser energy. Electrical measurement also shows that the electrical property such as electrical resistivity has a close relation with the graphitic sp2 clusters

Controllable Fabrication and Oil–Water Separation Properties of Polyethylene Terephthaloyl-Ethylenediamine-IPN-poly(N-Isopropylacrylamide) Microcapsules

In this paper, we report a microcapsule embedded PNIPAN in P (TPC-EDA) shell and it can be regarded as an interpenetrating polymer network (IPN) structure, which can accelerate the penetration of oily substances at a certain temperature, and the microcapsules are highly monodisperse and dimensionally reproducible. The proposed microcapsules were fabricated in a three-step process. The first step was the optimization of the conditions for preparing oil in water emulsions by microfluidic device. In the second step, monodisperse polyethylene terephthaloyl-ethylenediamine (P(TPC-EDA)) microcapsules were prepared by interfacial polymerization. In the third step, the final microcapsules with poly(N-isopropylacrylamide) (PNIPAM)-based interpenetrating polymer network (IPN) structure in P(TPC-EDA) shells were finished by free radical polymerization. We conducted careful data analysis on the size of the emulsion prepared by microfluidic technology and used a very intuitive functional relationship to show the production characteristics of microfluidics, which is rarely seen in other literatures. The results show that when the IPN-structured system swelled for 6 h, the adsorption capacity of kerosene was the largest, which was promising for water–oil separation or extraction and separation of hydrophobic drugs. Because we used microfluidic technology, the products obtained have good monodispersity and are expected to be produced in large quantities in industry

Beam position measurement system at HIRFL-CSRm

Beam position measurement system can not only provide the beam position monitoring, but also be used for global orbit correction to reduce beam loss risk and maximize acceptance. The Beam Position Monitors (BPM) are installed along the synchrotron to acquire beam position with the front-end electronics and data acquisition system (DAQ). To realize high precision orbit measurement in the main heavy ion synchrotron and cooling storage ring of heavy-ion research facility in Lanzhou (HIRFL-CSRm), a series of alignment and calibration work has been implemented on the BPM and its DAQ system. This paper analyzed the tests performed in the laboratory as well as with beam based on the developed algorithms and hardware. Several filtering algorithms were designed and implemented on the acquired BPM raw data, then the beam position and resolution were calculated and analyzed. The results show that the position precision was significantly improved from more than 100 μm to about 50 μm by implementing the new designed filtering algorithm. According to the analyzation of the measurement results and upcoming physical requirements, further upgrade scheme for the BPM DAQ system of CSRm based on field programmable gate array (FPGA) technology was proposed and discussed