Papers by Keyword: Focused Ion Beam (FIB)

Abstract: In this paper, nanosteps were fabricated by a new method. This method used the energy of focus imaging of focused ion beam to peel the material surface for fabricating the nanosteps. By changing the number of focus imaging can get different deepness nanosingle-steps. Changing the magnification, the second-step can be fabricated on nanosingle-step. An atomic force microscopy was used to measure the 3D morphology of nanosteps. When the magnification was 25000, the deepness of nanosingle-step was 65.34±3.00 nm and the deepness of the first step of nanodual-step was 56.03 nm. When the magnification was 50000, the deepness of nanosingle-step was 142.28±3.54 nm and the deepness of the second step of nanodual-step was 178.68nm. This means that the redeposition made the deepness of the first step become bigger, that of the second step becomes smaller. Based on comparison and analysis, the relation of the depth, the magnification and the number of the focus imaging were obtained.

Abstract: The correlation between intermetallic compound (IMC) and interface bonding state of the pure Al/08Al steel clad plate after 645°C/1h diffusion annealing was studied using the SEM. The results indicated that after 645°C/1h diffusion annealing for the pure Al/08Al steel clad plate, the IMC grew continuously along the interface with the thickness of 2-6 μm, while, at some regions grew abnormally with the thickness up to 10-30 μm. Moreover, some intrinsic defects at the interface, such as voids in the abnormally grown IMC and micro cracks along the interface were observed. The voids were possibly caused by huge difference of Al and Fe in diffusion coefficient, which is known as Kirkendall effect. On the other hand, the micro cracks could be attributed to the thermal stress during the cooling process because of larger difference of thermal expansion rate between Al and Al-Fe IMC. The intrinsic defects at the interface of Al/Steel could supply a novel way to correlate the morphology of IMC and interface bonding strength.

Abstract: The deformation behavior of the Γ (gamma) phase in the Fe-Zn system has been investigated via room-temperature compression tests of single-crystal micropillar specimens fabricated by the focused ion beam method. Trace analysis of slip lines indicates that {110} slip occurs for the specimens investigated in the present study. Although the slip direction has not been uniquely determined, the slip direction might be <111> in consideration of the crystal structure of the Γ phase (bcc).

Abstract: Atomic force microscopy (AFM) and focused ion beam technique (FIB) were adopted to study the early stages of surface relief evolution in 316L steel and polycrystalline copper fatigued with constant plastic strain amplitudes at different temperatures (316L steel at 93, 173 and 573 K; copper at 83, 173 and 295 K). Qualitative and quantitative data on the morphology and shape of persistent slip markings (PSMs), occurrence of extrusions and intrusions and the kinetics of extrusion growth are reported. They are discussed in relation with recent physically based theories of surface relief formation leading to fatigue crack initiation.

Abstract: The formation and the three-dimensional shape of slip bands in a fatigued dual phase steel were analyzed with the purpose of understanding the relation between fatigue crack initiation and the topography development on the specimen surface. Fatigue tests with small dog-bone-shaped specimens were conducted under fully reversed axial loading (R = -1) with a constant stress amplitude and were interrupted when the first slip bands occurred and at defined numbers of load cycles, respectively. Subsequently the surface topography of the specimen was investigated with a white light interferometer with hundredfold magnification and high numerical aperture (NA = 0.9) which allows analyzing the surface of individual grains. The results were confirmed by additional atomic force microscopy measurements. Based on this analysis the height, width and length of the slip bands are known at different stages of the fatigue process. The results obtained using white light interferometry and AFM, were checked by cutting individual slip bands with the help of focused ion beam thus revealing the true shape of the slip bands.

Abstract: The mathematical formulation of space-time energy release function of accelerated ions in solids is presented. High-power pulsed ion beam and continuous focused ion beam interaction with metals are considered. The power density of deposited energy and specific energy input in a target have been calculated. A beam energy fraction expended on the collisional sputtering of target atoms has been estimated.

Abstract: In this study, we generated the uniform diameter micro-bubbles using a piezo-vibration assisted capillary nozzle for apply the nano/micro bubbles device use. The capillary nozzle (diameter: 35 μm) was fabricated by FIB technique, and attached with piezo-device as micro bubbles generator. The fabricated piezo-nozzle showed inflective movement, whose displacement amount was about 3 μm. Micro bubbles were not able to generate from capillary nozzle without piezo-vibration, while micro bubbles, whose diameter was in the range of 20 μm to 21 μm, could be generated from the capillary nozzle with piezo-vibration.

Abstract: We demonstrated the fabrication of silicon nanowire (SiNW) sensors by focused ion beam (FIB) method and determined the effects of changes of nanowire parameters of width and wire-number on the SiNW electrical property. SiNW sensors were fabricated on a silicon-on-insulator (SOI) wafer with Au-Cr electrodes by the FIB method. We fabricated the SiNW sensor with a minimum width of 90 nm, length of 20 μm and height of 60 nm. The I-V characteristics in the state of ohmic contact were obtained, and the SiNW resistance was found to have 0.86 MΩ and a resistivity of 0.02 Ωcm. In addition, the electrical resistance dependence on width and wire-number was investigated. We found that wire conductance could be increased by increasing the wire-number and wire width.

Abstract: Solar cells of common sizes contains many of these defects and it is not easy to determine the influence of particular defects on the characteristics of the whole solar cell. Therefore, in our research we use samples of size of square centimeter at which we can disentangle the influence of the defect. We localize the defect by using a CCD camera, we measure the electrical, thermal and optical properties of the sample and then study it by means an electron microscope, we find the damaged structure and put it to focused ion beam. We expect the change in electrical, thermal and optical properties of the sample.

Abstract: Undoped and B-doped silicon-based nanowires (SiNWs) were synthesized by vapor-liquid-solid growth, and SiNW devices using Au electrodes were prototyped using focused ion beam (FIB) processing. Needle-shaped thin SiNWs were formed at a substrate temperature between 1170 and 1313 °C. The average and minimum diameters of the B-doped SiNWs were 72 nm and 52 nm, respectively. According to the current-voltage characteristics, SiNW devices have ohmic properties, and the estimated resistivity of the undoped and B-doped SiNWs are about 3.8 × 10³ Ωcm and 1.7 × 10³ Ωcm, respectively.