The Emerging field of nanoscale science, engineering and technology The WritePass Journal

The Emerging field of nanoscale science, engineering and technology 1.0 Introduction The Emerging field of nanoscale science, engineering and technology 1.0 Introduction1.1 History of the Focus Ion Beam (FIB) Technology1.2 Operational Overview1.3 Using Focus Ion Beam Systems 1.4 The Focus Ion Beam Instrument1.41 Ions in Operation1.42 Gallium (Ga+) Ions2.0 Focus Ion Beam System2.1  Ã‚   The Column2.2 Lens System2.3 Generation of Image2.4 Detector, Stage and Gas Injection2.5  Liquid Metal Ion Source (LMIS) 2.5  Milling2.7 Sample Preparation2.8 Imaging3.0   Conclusion Related 1.0 Introduction The Emerging field of nanoscale science, engineering and technology – that is the ability to work at the atomic, molecular and supramolecular levels, to create large structures with fundamentally new properties and functions have lead to an unrivalled understanding and control over basic building blocks of all natural and man-made things [roco]. This rapid advancement has lead to an increased demand for technological development on a nanoscale, which has brought about the birth and improvement of infrastructural changes aimed at representing and observing these features. The world wide focus over this time has been the evolution of methods including SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope), FIB (Focus Ion Beam) etcetera for the detailing of features at the nanoscale. 1.1 History of the Focus Ion Beam (FIB) Technology Focus Ion Beam (FIB) systems have been commercially produced, mostly for manufacturers of large semiconductors for about 20 years [www.fibics.com]. In 1982, Anazawa et al. produced a 35Kv Ga- source and about three years later Orloff and Sudruad proposed FIB system for implantation and lithography [sudruad], even though as of 1959, Feyman had suggested the use of ion beams [www.nanofib.com]. In 1985, Kato et al. have pointed out the advantages of the FIB technology in the fabrication of sub-micro structures. 1.2 Operational Overview The operation of the FIB are same as that of SEM (Scanning Electron Microscope), except that the focus ion beam system employs the use of focussed beam of   ions instead of beam of electrons utilised in the SEM systems[]. Commercialised nanoscience is limited by availability of tools. Using focussed ion beam system allows specified fabrication and imaging abilities which reduces greatly the characterization cycles and development required in the nano-technological field by scientist. The capabilities within focus ion beam ( FIB) are valued highly for rapid prototyping application. The deposition combination / direct etching of FIB in combination with digitally addressed patterning system allows nano prototyping engine with capabilities that will help researches in nano technology , because the operation of FIB is on both micro and nano scale, it can be used in creating the required structures. FIB has prà ©cised control over deposition and milling parameter and as such, it is the proper tool for creating small structures for nano technology in the top –down approach. It is a highly flexible, mask-less technique which is fast for serial techniques, thus allowing the FIB instrument very efficient for design modifications. Most conventional methods of sample preparation used today in life sciences are compatible with investigations by using FIB. 1.3 Using Focus Ion Beam Systems The direct applicability obtained in using FIB instrument is highly relevant in industrial applications. FIB instrument and its application have contributed immensely to industrial researches carried out in several analysis laboratories For instance in the polymer industry, metallurgy industry, nuclear research etcetera. The ability to image, mill and deposit material by using FIB instrument depends largely on the nature of the ion beam- solid interactions. Milling occurs as a result of physical sputtering of the target. In understanding the mechanism of sputtering we need to consider the interaction between an ion beam and the target. Sputtering usually takes place when there is elastic collision in series when momentum is transferred from the incident ions to the target atoms in the region of collision cascade. Ionization of a portion of the ejected atoms can be collected for mass analysis or image formation. Production of plasmons (in metals), phonons and emission of secondary el ectrons can occur as a result of inelastic scattering. Imaging in the focus ion beam is carried out by detecting the secondary ions/electrons typically, sputtering in focus ion beam processes occurs within energy ranges that are dominated by nuclear energy losses. Focus Ion beam devices are used to scan the surfaces of samples using simple focussed ion beams. The detection of secondary ions allows the processed surface of samples and microscopic images to be observed. The ion beam is generated by using liquid metal ion source (LMIS) when a beam of ion is irradiated on the surface of a specimen by finding the secondary ions with a detector a two dimensional distribution which shows the microscopic images of the surface of the specimen can be observed. 1.4 The Focus Ion Beam Instrument The Operation of the FIB technology uses a similar principle as the SEM (Scanning Electron Microscope) / TEM (Transmission Electron Microscope) but differs in the use of ions and this introduces consequences of enormous magnitude for interaction which occur at the surface of the specimen. Using Focus Ion Beam (FIB) instrument involves two major parameters – penetration of ion into material and the rate of sputtering of ion of the material. When the emitted liquid metal ion source (LMIS) primary ion beam hits the surface of the specimen, it splutters a small amount of material this will leave the specimen surface as either neutral atoms or secondary ions – Secondary beams are also produced using the primary beam. Signals from the sputtered ion or secondary electron are collected to produce an image as the primary beam raster on the specimen surface. Liquid metal ion source (LMIS) development is crucial for the development of Focus Ion Beam (FIB) [www.dspace.cam.ac.uk] , application of electric field that are very high into a steering quadrupole, octupole deflector, two electrostatic lenses in the column   to focus ions in a beam and scan the beam on the specimen. Liquid metal ions source (LMIS) generates ions; these ions are focussed on electrostatic lenses. When specimen surfaces are bombarded using ions that have been extracted from the liquid metal ion source (LMIS) this generates ions, secondary electron and sputtered material and the various generated items serve different purpose in the focus ion beam. At high primary currents a large amount of material can be removed by sputtering thus allowing precision milling of the specimen down to the submicron scale, while less material is removed at low primary beam currents. The use of ions in focus ion beam instruments means that they cannot penetrate with ease individual atoms of the specimen because ions are large. So interaction usually occurs within outer shell interaction which causes chemical band breakage of the substrate atom and atomic ionization. Inner shell electrons of the specimen cannot be reached by an incoming ion. The probability of an interaction with atoms that are within the specimen is much higher because of the large ion size and this result in rapid loss of energy of the ion. This means that the depth of penetration is much lower. It should be noted that the main advantage of   the Focus Ion beam is its ability to produce image of the sample after which it mills the sample precisely away from the areas that are selected[ ]. 1.41 Ions in Operation Ions are slower when paired to electrons for the same energy, because they are much heavier as a result Lorenz force is lower, so the use of magnetic lenses is less effective, and as such the focussed ion beam instrument is equipped with electro static lenses. Ions are positive, slow, large and heavy; so the resulting ion beam will remove atoms from the substrate and because the size, beam position and dwell time are well controlled, it can be used in the removal of materials locally in a manner that is highly controlled down to the nanoscale. As a result of the actions due to the ions used in the Focus ion beam instrument, fabrication and imaging functions are derived. The fabrication function occurs due to the sputtering while the imaging function arises due to the ions and secondary electrons. 1.42 Gallium (Ga+) Ions The gallium ions are used in the focus ion beam (FIB) instruments for the following reasons [fei]; Due to its surface potential it exhibits very high brightness, the tip sharpness, the flow properties of the gun and the gun construction which results in field emission and ionization. This is an important result for the focussed ion beam. It should be noted that whatever chosen material should be ionized before the formation of the beam and then accelerated. The element Gallium is metallic and because of its low melting temperature is a very convenient material for compact gun construction with limited heating. Gallium is the centre of the periodic table and exhibits an optimal momentum transfer capability for a wide range of materials, lithium which is a higher element will not be sufficient in milling of heavier elements. Gallium element has low analytical interference 2.0 Focus Ion Beam System In the figure below, the FEJ 200 series type F113 of the FIB system is represented. In the figure are the various components of the system which includes the column, the specimen chamber and the detector; 2.1  Ã‚   The Column This is situated above the specimen chambers. It is made up of   two electrostatic lenses, a set of beam blanking plates, liquid metal ion source (LMIS), a beam acceptance aperture, steering quadrupole, beam defining aperture and an octupole deflector. 2.2 Lens System Coming from the source, the beam goes through a beam acceptance aperture after which it goes into the first lens. Above the beam- defining aperture (BDA), the quadrapole adjust the position of the beam in a manner as to allow the beam move through the center of the beam-defining aperture (BDA). The beam is aligned to the optical axis of the second lens’ quadrapole. Beam astigmatism correction, shift and scanning is provided by the octupole which is positioned below the second lens. Between the second lens assembly and the second lenses steering quadrapole we have the beam blanking assembly. This is made up of aperture and electrical path and blanking plates. Beam blanking provides specimens with protections against constant milling. 2.3 Generation of Image The primary beam is scanned as a raster across the specimen and it is made up of lines in vertical axis (shifted slightly from one another) and lies in the horizontal (in series). With scanning of the beam over the specimen the secondary ions and the secondary electrons that are generated by the specimen are detected. Details of this information are stored in the computer and images are produced from these information. 2.4 Detector, Stage and Gas Injection Control of rotation and X and Y axis is performed by software and it can be tilted to the XY plane manually. Gases of two types are evolved above the surface of the specimen at about 100 µm of distance. One of these gases is used for platinum deposition and the other for enhanced etch. During bombardment of ion in milling, species that are charged are formed and they are attracted to the detector. A glass of millions of arrays of minute channel electron multiplier is the detector; it is a micro channel plate (MCP). 2.5  Liquid Metal Ion Source (LMIS) LMIS is made of a needle emitter which has an end radius of 1 10 µm. It is coated with high surface tension metal which at its melting point has a low vapour pressure. This emitter is subjected to heating till the melting point of the metal is attained. A positive high voltage is placed on it. Using the balance between the surface tension forces and the electrostatic the liquid metal is drawn into a conical shape. The source that is commonly used is Gallium [dspace.mit.edu]. 2.5  Milling By using the scan control system, polygons, circles and lines can be milled. The table below represents the different beam currents and their corresponding milling spot sizes. The figure below gives us the pixel size and milling spot size and the beam overlap.   The overlap can be expressed as the overlapped area where the beam moves from a position to the other. And the time where the beam remains in a position is known as the dwell time.    2.7 Sample Preparation The three main strategies used in the focus ion beam sample preparation of specimen that will be inspected using TEM are: Ex situ lift-out (EXLO) preparation (Centre Image), H-Bar sample preparation (Left image) and In Situ lift-out (INLO) preparation (Right image) [info.omniprobe.com/blog/bid] 2.8 Imaging When ion beam is scanned on the surface of the specimen, it causes ions and electrons to be ejected. After scanning through the surface of the specimen the primary Gallium ion penetrate into the surface of the specimen. The depth of the penetration varies from one material to the other. The secondary electron yield is much higher than secondary ion yield during ion milling and thus is the reason why focus ion beam is usually used in the secondary electron mode. Secondary ions and secondary electrons are obtained within regions that are closer the surface of the specimen. 3.0   Conclusion In their work on the future of focus ion beam, the ORSAYPHYSICS group has shown that field of focus ion beam is open to expansion. Their projections with regards the extent to which focus ion beam can be deployed is shown in the figure below: Fig.     Ã‚   Current and Future FIB Technologies Source: felmi-zfe.tugraz.at/FIB/WS3_Beitraege/01%20Sudraud.pdf The use of FIB has been developed extensively over the years in applications like super conductor, field emission device, accelerometer etcetera. Armed with imaging capability of high resolution as its recently upgraded technologies, the focus ion beam (FIB) instrument is indeed technology that is providing solutions to problems that has been previously unresolved. This heralds the focus ion beam (FIB) instrument as an important device for the future in the nano science, technology and engineering environment.

10+ Tools and Resources to Write the Perfect Resume

10+ Tools and Resources to Write the Perfect Resume 10+ Tools and Resources to Write the Perfect Resume 10+ Tools and Resources to Write the Perfect Resume By Ali Hale If you read my post of resume tips a few weeks ago, you’ll already be familiar with best practice for writing a great resume. While there’s nothing wrong with hand-crafting your resume in Microsoft Word (or your word processor of choice), there are plenty of online tools that can save you lots of time by formatting your resume in seconds. Plus, if you’re still struggling with exactly what to put on your resume in the first place – there’s lots of great advice out there. Before we get into the list of great tools and resources, there are a couple of crucial things to keep in mind: Whatever tools you use, employers will expect a resume that conforms to a standard format. There are some nifty tools out there that let you create a resume that looks like, say, an infographic: unless you’re very certain that’ll go down well with your potential employer, stick to something a little more conventional. Tools can be hugely helpful but they can only do so much. If there are major issues with your resume (like a huge unexplained gap in your work history, or a total mismatch between your listed skills and what an employer wants), you’ll want to fix those problems before trying to format your resume beautifully. With those caveats out of the way, here’s the list: Online Advice and Support on Creating Your Resume #1: â€Å"Resume† Category (free), Ask a Manager I love the blog â€Å"Ask a Manager† by Allison Green (though be warned, it’s an easy place to spend a little too much time reading about other people’s weirdly dysfunctional workplaces). There’s a whole category of advice about â€Å"Resumes†, which is well worth a read. (Allison Green is a manager who’s been extensively involved in hiring and really knows her stuff. You can submit your own questions to her, if you have a resume query that hasn’t already been covered on the blog.) #2: Resume Samples (free), Resume Genius If you’re writing a resume for the first time – or after a long time away from employment – then you might feel quite unclear on how a resume should even look. Going through some resume samples can be really helpful, because it gives you a good feel for what potential employers will expect. There are plenty of sites out there offering sample resumes, but Resume Genius is a particularly easy-to-use one, with samples categorised by industry, and with related samples like cover letters, plus additional tips. You can click to download a sample as a Microsoft Word document without having to sign up or put in your email address. Tip: Don’t assume that the wording or layout of a sample is perfect (or that it’s perfect for the role you have in mind): it won’t necessarily be appropriate to copy a particular phrase that a sample resume or cover letter uses, for instance. In any case, you should be very careful about using wording from any sample unless it’s something very standard (like â€Å"I am interested in applying† or â€Å"Thank you for your consideration†), unless you have express permission – otherwise, copying the sample is plagiarism. #3: CV Tips: this is what a recruiter can see after 30 seconds with your resume (free), The Independent This is a single article, but one I wanted to link to because it provides a very honest and valuable perspective from the other side of the fence. It’s easy to end up agonising over things on your resume that don’t really matter – or giving too much importance to areas that employers simply aren’t that interested in (like your educational history). Tip: Although published by a UK newspaper, the author of the piece (Ambra Benjamin) is American, so the advice here applies fairly well on either side of the Atlantic. #4: 43 Resume Tips That Will Help You Get Hired (free), The Muse This is another single article, but one that’s packed with practical tips and lots of links to further information, from the big picture (focusing on recent, relevant jobs) to the little details (avoiding using the same words repeatedly). Note that the article is aimed at US readers, so if you’re in a different country, you may find that some of the advice doesn’t necessarily apply – and even if you are in the US, don’t feel that you have to follow every single point slavishly. Give this a skim-read when you’re first putting together your resume; you can then go through it point by point as you edit and polish your resume, following the links to further information if there’s a particular area where you need extra help or want more details. Tip: There’s some particularly good advice towards the end of the article about saving and sending your resume – do make sure that it displays correctly once emailed (you can send it to yourself and check it on another computer), and make sure you include your name in the file name, not just â€Å"Resume† or â€Å"CV†. #5: 103 Resume Writing Tips, Resume Genius This piece, like the one from The Muse, collects together lots of practical tips – with links to further help when needed. It’s a little different, though, in that it’s a collection of common mistakes – things that the team at Rescue Genius see on a daily basis when reviewing people’s resumes (like â€Å"forgot to use action verbs† or, worryingly, â€Å"misspelled own name†). Some of the mistakes might seem like obvious ones to avoid, but others are ones you might never have thought about before – like â€Å"weak bullet points displayed before strong ones† and â€Å"not bringing multiple copies of it to interview†. Tip: The article is US-focused, but a lot of these tips will apply wherever you are in the world.   There might be cases where standard practice in your own country is different, though – so do seek local advice as well, and ignore the tips/mistakes that don’t apply to you. Tools to Create Your Resume #6: Canva Resume Builder (free) Canva offers a wide range of design tools and resources, and it has a great resume building tool. You start by writing your name and then you will be able to pick the style you are looking for. For example, you can go with corporate style, acting resume, high school, creative professional and so on. The next step is to pick the templates you like from a list of available ones. Finally, you will be able to input your resume information and to edit any design aspects you want. Overall the process is very simple and will produce a professional looking resume in a very short time. #7: Google Docs templates (free), various creators If you want a straightforward way to create a resume, why not use Google Docs’s templates? Click on the link above to go straight to the â€Å"Template gallery†, then click â€Å"General† to view them. You should see a whole series of different templates: scroll down to get to the resumes. Click your chosen template to load it up, then simply fill in the details. Keep in mind that once you’ve chosen a template to edit, you can’t switch your text to a different template – so you might want to try a few before you settle on one. Tip: Most of the resume templates have a corresponding â€Å"letter† template that uses the same colours and fonts. You might want to use this for your cover letter (if you’re not simply including the cover letter in the body of an email). #7: Kickresume (free/paid), Kickresume SRO Kickresume is a free and straightforward site that lets you create a standard resume, providing templates for both resumes and cover letters (plus websites). It’s simple to use, though you will need to create an account (or you can login via Google, Facebook or LinkedIn). To save time, you can import your LinkedIn profile, by downloading a .zip file from LinkedIn and uploading it to Kickresume – full instructions are provided. You can change the template you’re using at any time, without losing any of the text you’ve uploaded or inputted. There are only three basic, free templates though – if you want to use the â€Å"pro† options, you’ll need to upgrade to the paid plan ($15/month or $48/year). Tip: Some of the resume templates include space to put a photograph of yourself. This isn’t standard practice in the US or UK for resumes, so if you’re in those countries, you may want to choose a template that only has text content. #9: Enhancv (paid, has free trial) Enhancv is a complete platform for those looking to create a modern and effective resume. After signing up you will be prompted to choose one of the many existing templates. you will then be able to edit all the sections with your personal information and experience. One interesting feature the platform offers are the automated suggestions to improve the wording of specific parts of your resume. This is a paid product, but it comes with a free 7-day trial. On top of that the website offers a wide range of resources and articles you can use to improve your resume without paying anything. #10: CV Maker (free, paid), CV Maker CV maker offers several basic templates for creating a resume. You fill in your information in a form, and you can then switch between different templates if you want to. While it’s possible to create your resume without logging in, you’ll need to create an account if you want to save your CV and edit it in the future. It’s free to create an account, and you’ll get full access to the basic templates and to the save/download features. The premium level (which gives you lots of advanced options) only costs $16/year, too – so you might decide it’s worth upgrading. Tip: CV Maker’s site is available in a wide range of different languages: if English isn’t your native language, you can easily change this from the drop-down menu at the top of the site or the list in the footer. #11: Standard Resume (free, paid), Minimum Works Standard Resume has a very straightforward LinkedIn import – you can bring in all your information from LinkedIn, then edit or add anything you need to. As with Kickresume and CV Maker, the basic templates are free; you can pay for a premium account ($5/month or $20/year) to tailor your resume further. Unlike some other sites, Standard Resume keeps the templates simple and straightforward: you won’t find profile photos or odd infographic elements here. If you’re applying to a fairly traditional industry, or if you just want to keep things as simple as possible, that could make Standard Resume a great option for you. Tip: The pro level also lets you see when your resumes have been viewed and/or downloaded, which you might find useful. #12: Slick Write (free), RussTek LLC In Top 10 Online Tools to Help You Write the Perfect Essay, I covered the popular spelling and grammar checking tools Grammarly and Hemingway. Slick Write is similar: you can paste in a passage of writing (or use a Chrome or Firefox extension) and it will automatically flag up potential problems. You could use it on your cover letter or any emails you need to send, as well as on your resume. While I don’t think any tool can replace careful proofreading – and ideally, a second pair of eyes on your resume – Slick Write can help you to edit your work. It’s completely free, so well worth a try. (It is, however, funded by ads, which you may find slightly intrusive or annoying.) Tip: As with any grammar checker, don’t feel that you have to follow every single recommendation. You might decide that your phrasing is fine as it is! Whatever tools you use to help, writing a resume can be tough. You need to convey, clearly and concisely, exactly why you’ll be a good fit for a particular role – in a standard format that supplies potential employers with all the information they’ll expect. For further help on knowing what to include in your resume, take a look at my article Top 10 Resume Writing Tips for 2018. Best of luck with your job-hunting. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! 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