2006 19th International Vacuum Nanoelectronics Conference最新文献

{"title":"Atom Probe Tomography Characterization of a Gas Atomized Metallic Glass","authors":"M. K. Miller, S. Venkataraman, J. Eckert, L. Schultz, D. Sordelet","doi":"10.1109/IVNC.2006.335295","DOIUrl":"https://doi.org/10.1109/IVNC.2006.335295","url":null,"abstract":"Summary form only given. A number of metallic glasses that exhibit a wide supercooled liquid region before crystallization and a high glass-forming ability have been discovered. These metallic glasses exhibit useful properties such as high strength and high stiffness and can be fabricated from the melt in a bulk form with a thickness of ~ 10 mm. The high glass-forming ability facilitates the formation of metallic glass powders by conventional gas-atomization technique. Subsequent consolidation of the powders to any dimensions is possible due to the viscous flow of the material in the supercooled liquid region. Hence, the synthesis of bulk metallic glasses using gas atomization coupled with subsequent consolidation holds a promising future. Atom probe tomography, X-ray diffraction and differential scanning calorimetry (DSC) characterizations of gas atomized powder particles of a Cu47 Ti33Zr11Ni8Si1 metallic glass have been performed. The needle-shaped specimens required for the local electrode atom probe were fabricated from individual 10-40 mum diameter particles with the use of a dual beam focused ion beam miller. The microstructure of the alloy was investigated from the as-atomized powder and annealing treatments up to the completion of the first and second exothermic events at 785 and 838 K. Atom probe tomography revealed that the microstructure consisted of an interconnected network structure of two amorphous phases after an annealing treatment of 360 min. at 623 K. A fine-scale multiphase microstructure of an irregularly shaped copper-enriched and titanium-, nickel- and silicon-depleted phase that was 10-20 nm in extent, a higher number density of smaller, ~10 nm diameter, and roughly spherical titanium-enriched and copper- and zirconium-depleted phase and a matrix phase was found after continuous heating in a DSC to 785 and 838 K. The scanning electron microscope also revealed 4 distinct coarser phases consistent with Cu51Zr14, CuTi, (Cu,Ni)Ti and an unidentified structure after annealing for 24 h at 1073 K","PeriodicalId":108834,"journal":{"name":"2006 19th International Vacuum Nanoelectronics Conference","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126043144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the Driving Characteristic of CNT Triode with High Frequency","authors":"Weiqiang Chai, C. Lou, Qilong Wang, W. Lei, Xiaobin Zhang","doi":"10.1109/IVNC.2006.335253","DOIUrl":"https://doi.org/10.1109/IVNC.2006.335253","url":null,"abstract":"The driving characteristic of a carbon nanotube field emission triode is analyzed using RF-PSPICE model. A circuit model of the triode is proposed","PeriodicalId":108834,"journal":{"name":"2006 19th International Vacuum Nanoelectronics Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126045391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomic Scale Characterisation of GP Zones in the Fe-Nb-(C-N) System","authors":"F. Danoix, E. Courtois, F. Vurpillot, T. Epicier","doi":"10.1109/IVNC.2006.335389","DOIUrl":"https://doi.org/10.1109/IVNC.2006.335389","url":null,"abstract":"In this paper, the first experimental evidence of GP zones in a very dilute Fe-Nb-C-N model high-strength low alloy (HSLA) were demonstrated, where the precipitation sequence is started from a random solid solution under the simple action of temperature during ageing. Combining high-resolution transmission electron microscopy (HRTEM), field-ion microscopy (FIM) and atom-probe tomography (APT), the GP zones were shown to be one monolayer in thickness, and that their composition is essentially NbN based. This result demonstrates - similarly to what is observed in Al based alloys - that GP zones can also act as the onset of phase transformation sequence in steels. This result is also of particular importance for the class of HSLA steels, the mechanical properties of which are commonly optimized by a fine dispersion of metallic carbo-nitrides. Taking advantage of this new precipitation mechanism leads to new perspectives for improving their mechanical properties","PeriodicalId":108834,"journal":{"name":"2006 19th International Vacuum Nanoelectronics Conference","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126872165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Influence of Silicon on the Precipitation Process in Maraging Stainless Steels","authors":"Marcus Andersson, K. Stiller, M. Hattestrand","doi":"10.1109/IVNC.2006.335384","DOIUrl":"https://doi.org/10.1109/IVNC.2006.335384","url":null,"abstract":"Using the Sandvik alloy 1RK91 as a reference material, a new test alloy with higher silicon content (Si+) was produced. Its hardness after 5 minutes at 475degC is more than 45% higher than that of the unaged alloy. The Si+ alloy shows no sign of softening during the ageing process up to 100 hours and by this time reaches the hardness of 650 Vickers. To understand these remarkable mechanical properties, the precipitation process of the new alloy has been investigated using energy-compensated tomographic atom probe analyses, local electrode atom probe analyses and energy-filtered transmission electron microscopy, and results were compared with those obtained from the investigations of alloy 1RK91","PeriodicalId":108834,"journal":{"name":"2006 19th International Vacuum Nanoelectronics Conference","volume":"163 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128088047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First steps in ultrafast laser assisted atom probe tomography","authors":"B. Gault, F. Vurpillot, A. Vella, A. Bostel, A. Menand, B. Deconihout","doi":"10.1109/IVNC.2006.335346","DOIUrl":"https://doi.org/10.1109/IVNC.2006.335346","url":null,"abstract":"Summary form only given. With the development of on-table ultrafast lasers delivering high energy pulses with a duration of a few hundreds of femtoseconds, a new generation of laser assisted tomographic atom probes (TAP) is born in the last two years. The use of ultrafast laser pulses seems to be the most promising way to overcome all the classically admitted shortcomings of the atom probe technique. The mass resolving power is greatly enhanced due to the decrease of the pulse length. This gives the opportunity to decrease the flight length to increase the field of view of the TAP. Moreover, atom probe techniques are not really adapted for semiconductors or insulators analysis, because of problems caused by the high voltage pulses propagation in non-good conductive material. The opportunity to generate the pulsed electric field directly at the apex of the specimen by using ultrafast laser pulses should theoretically open the technique to this kind of materials. The feasibility of ultrafast laser TAP analysis on both metallic and semiconductor materials was demonstrated. But the physical phenomenon involved the ultrafast laser assisted field evaporation had to be well understood and characterised. The tip dimensions with respect to the wavelength of the laser give rise to intrinsic laser electric field enhancement at the tip apex. We demonstrated that this effect was pregnant in the case of TAP specimen. An original field evaporation process based on a non-linear second order optical effect was also proposed and demonstrated. The thermal effects due to laser absorption by the material are not supposed to generate field evaporation. In this contribution, the field enhancement phenomenon will be presented, the field evaporation process will be evoked, and finally, advantages brought by the use of ultrafast laser pulses for atom probe analysis will be discussed","PeriodicalId":108834,"journal":{"name":"2006 19th International Vacuum Nanoelectronics Conference","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131049850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Why do We Need a High Performance Position Sensitive Detector in Atom Probe Tomography?","authors":"F. Vurpillot, G. da Costa, F. De Geuser, B. Gault, B. Deconihout","doi":"10.1109/IVNC.2006.335328","DOIUrl":"https://doi.org/10.1109/IVNC.2006.335328","url":null,"abstract":"Summary form only given. We have studied the correlation between field evaporated atoms during an atom probe tomography experiment. The evaporated atoms have been shown to be highly correlated both in time and in space. This correlation can be explained by the dynamic distribution of the electric field at the surface of the sample. The distance of correlation between successively evaporated atoms corresponds to the mean size of this zones and the time of correlation corresponds to the mean time necessary to evaporate the entire zone. These zones are most likely to correspond to atomic terraces. These strong correlations in time and in space are the sources of high stresses for position sensitive detectors. A detector with high spatial and time resolving power is required in order to obtain quantitative composition measurement in atom probe tomography","PeriodicalId":108834,"journal":{"name":"2006 19th International Vacuum Nanoelectronics Conference","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115701295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Dualbeam (FIB/SEM) and its Applications - Nanoscale Sample Preparation and Modification","authors":"P. Lawrence","doi":"10.1109/IVNC.2006.335390","DOIUrl":"https://doi.org/10.1109/IVNC.2006.335390","url":null,"abstract":"Summary form only given. The ability to modify samples and create structures at the `nano' level (<100 nm) is now a very well established science. However, the tools required to facilitate this technology are going through a constant evolution in order to keep up with the high demands of new applications. One such tool is the Dualbeam, which combines a field emission SEM column with a gallium source focussed ion beam (FIB) column. Previously used only in the semiconductor or `nano-electronics' industry, it is now a vital tool in creating, modifying, imaging and analysing structures at the nano scale. In fact Dualbeams systems are now used regularly in semiconductors, data-storage, research, industry and even biology. Having two beams offers tremendous advantages to the user. A SEM column is the ideal tool for sample inspection and for imaging at high resolution of specific features without the risk of sample damage. By aligning the SEM and FIB at a reference point the sample can be inspected non-destructively and a certain area of interest determined. Software patterns are used to control where and how the ion beam is scanning on the sample and therefore where material is being removed. The milled area can be imaged in real time by the electron beam while the milling is in progress. This `simultaneous patterning and imaging' can be very useful to carefully control the milling process, using the ion beam only for material removal and the electron beam for non-destructive observation. An extension of the imaging and milling capability is called Slice and View. This allows an image to be recorded each time a `slice' of material is removed by the ion beam. The result is a stack of images taken through a selected area of a sample, showing information in x, y and z dimensions. However, true 3D information can be seen if the images are processed using reconstruction software. One of the most important applications of a dualbeam is that of quality TEM sample preparation. With the aid of the electron beam - the ion beam can be placed very accurately and site specific TEM sample preparation is possible. Recently the development of Cs corrected TEM systems has meant that TEM sample quality is now of high importance if quality data is to be gained. Using low kV ion beam energies the sample damage often associated with high kV preparation can be virtually eliminated. In situ lift out techniques, such as the Omniprobe, allow the sample to be removed and attached to a grid inside the chamber, allowing for further thinning and polishing of the sample wherever necessary. The ion beam can also be used to modify or produce tools for use in a variety of applications. Examples might be the production of super fine needles in the medical field, for producing micro-indenters for materials research, or for creating/modifying an AFM tip. In many cases the combination of beams may produce the best results. For example, the AFM tip may be further enhanced by depositing a s","PeriodicalId":108834,"journal":{"name":"2006 19th International Vacuum Nanoelectronics Conference","volume":"234 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122621072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evidence of Field Evaporation Assisted by Nonlinear Optical Rectification Induced by Ultra Fast Laser","authors":"A. Vella, B. Vurpillot, B. Gault, A. Menand, B. Deconihout","doi":"10.1109/IVNC.2006.335368","DOIUrl":"https://doi.org/10.1109/IVNC.2006.335368","url":null,"abstract":"We investigate the physical mechanism of the field ion emission in the case of ultra-fast laser pulses which is based on the nonlinear optical properties of surfaces: the optical rectification effect on metal surface. The optical rectification is based on nonlinear second order processes which occur in all non-centro-symmetric materials and at the surface of metals where the electronic density of states exhibits a discontinuity that yields strong anharmonic and nonlinear effects. Several experiments have been realised on tungsten and aluminium tips. A good agreement between the model and experimental data is found","PeriodicalId":108834,"journal":{"name":"2006 19th International Vacuum Nanoelectronics Conference","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126903594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leap® Characterization of the γ-γ' Interface in Crept and Annealed CMSX-4 Nickel Based Superalloy","authors":"M. K. Miller, R. Reed","doi":"10.1109/IVNC.2006.335415","DOIUrl":"https://doi.org/10.1109/IVNC.2006.335415","url":null,"abstract":"Summary form only given. Rhenium additions have played an important role in improving the high temperature properties of nickel-based superalloys. Previous atom probe and transmission electron microscopy characterizations have demonstrated that Re strongly partitions to the γ matrix where it acts as a solid solution strengthener. Blavette et al., found evidence of 1.3 nm diameter Re clusters in classical atom probe data from the γ matrix. More recently, Re clusters containing ~10% Re were found to be located preferentially in an ~10-nm-wide Re-enriched γ region close to the γ-γ' interface. The cuboidal L12-ordered primary γ' precipitates evolve during extended creep into extended rafts perpendicular to the tensile axis. A local electrode atom probe has been used to characterize the solute distribution along and normal to the γ-γ' interface in a crept and annealed CMSX-4 nickel based superalloy. The creep tests were performed under a tensile stress of 185 MPa at a temperature of 950°C. The tests were interrupted at times of 285, 550, 695, 1060 and 1170 h. Atom probe specimens were cut from the gauge section of the creep specimens both parallel and perpendicular to the tensile axis. Annealed specimens were also cut from the grip sections of the creep specimens. Comparison of the Al isoconcentration surfaces revealed that the γ-γ' interface was relatively smooth for the annealed conditions but featured steps and grooves in the crept conditions. Concentration profiles constructed normal to the γ-γ' interface from selected volumes encompassing only flat regions of the interface revealed significant solute enrichments of most alloying elements close to the interface. Ultrafine (~1 nm diameter) rhenium clusters containing up to ~10-15% Re were evident in the 10-nm wide Re-enriched region in the matrix close to the γ-γ' interface. Re-enriched regions were also detected in asperities in the γ-γ' interface in the crept conditions.","PeriodicalId":108834,"journal":{"name":"2006 19th International Vacuum Nanoelectronics Conference","volume":"278 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114486421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Standard Deviation of Composition Measurements in Atom Probe Analysis","authors":"F. Danoix, G. Grancher, A. Bostel, D. Blavette","doi":"10.1109/IVNC.2006.335324","DOIUrl":"https://doi.org/10.1109/IVNC.2006.335324","url":null,"abstract":"Summary form only given. Atom Probe is a unique instrument to measure concentrations in metallic materials in volumes ranging from one to several ten thousands cubic nanometers. It can be used to measure the local concentration of the whole analysed volume, or to estimate the alloy composition. The list of detected atoms can be segmented into equal sized (in terms of number of atoms) sub-blocks, in which local composition is measured, leading to classical concentration profiles. Alternatively, due to the positioning capabilities of 3D atom probes, composition measurements can be focused on spatially selected areas, or concentration profiles calculated over constant sampling volumes. As each of these measurement procedure is different (as well as the information to be estimated) the variances of the obtained compositions should be estimated accordingly. This contribution is devoted to derive analytical expressions of the variance in several standard situations encountered when using atom probe. The particular aspect of the influence of the detector efficiency (which is generally not equal to unity...) on the estimates of composition measurement accuracy will be discussed","PeriodicalId":108834,"journal":{"name":"2006 19th International Vacuum Nanoelectronics Conference","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134124950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}