Thin Films and Nanotechnology

Thin Films and Nanotechnology

  • Manal El-Sheikh added an answer:
    Why I can not find a UV-Vis band for polyaniline?

    I am preparing AgNPs/PANI nanocomposite. I can see the brown yellow color of AgNPs during synthesis and the green-violet color of PANI (emeraldine) after precipitation with ethanol. I can also see a pure uniform silver metal after ethanol precipitation. I can detect the UV-Vis band for AgNPs in aqueous solution but I cannot detect a UV-Vis band for emeraldine either in ethanol or in water. 

    Manal El-Sheikh · National Research Center, Egypt

    Thank you all for your valued answers, for your time and for transferring your expertise not only to me but also to every one followed the question. It is really a very good discussion. Thanks to: Sunil Dutt,  Rinkesh Bhatt,  Jiri Vohlidal, Abdussallam Eldewik, Dr. S. Kalidhasan, Uday Chand Ghosh, Mircea Chipara, Asit Baran Samui, Bernhard Wessling, Cun Li, and Daniela Gogova. 

  • Sandeep Thakare added an answer:
    How to search data of xrd from JCPDS number?
    I want to know how to search data if I know JCPDS number.
    Example I knew my JCDPS number it's JCDPS #800075.
    I want to use data with my XRD research graph.
    Sandeep Thakare · Indian Institute of Technology Bombay

    What is JCPDS card no. for Ti6Al4V?

  • Nilesh Kulkarni added an answer:
    Any insights on the comparison between Vantec 500 (Bruker), Pilatus 100K (Rigaku) and PIXcel 3D (PAN)?
    May I get your opinion on 3 type detector above? I need feedback from researcher, not manufacturer.

    Thanks.
    Nilesh Kulkarni · Tata Institute of Fundamental Research

    I can comment on 1D detecor Xcelerator from Panalytical. I have been using this detector for last 11 yrs and performance is awesome. Pixel 3D is next generation from Panalytical and it is superior to Xcelerator.  I have not used Vantec / Pilatus.

  • Sai Jiao added an answer:
    Can anyone help me find magnetron reactive sputtering information on group III-Nitrides?

    Is there anyone who have experiences using DC Magnetron Reactive Sputtering Systems from the Germany based Company Singulus? What about their AlN ability specifically? and Could you give me some typical material properties if you are one of the users of Singulus Systems? Thanks.

    Sai Jiao · Tohoku University

    Thanks Hamida, Actually, What I was looking for was some process and equipment settings for specific Reactive Magnetron Sputtering System from Singulus Technology (DE). Cause apparently they claim to have the ability to install this kind of system for Nitrides Deposition. but I couldn't find any public document for it.

    Anyway, thanks a lot for your attention.  

  • Is it logical to use Ti-Nanoxide-HT (Solaronix) for solution state quenching studies?

    The Commercially available Ti-Nanoxide-HT from solaronix brand containing an organic binder. If we use it for quenching studies, will the binder influence our result? What I am thinking is that we are coating the Ti-Nanoxide-HT (containing the binder) on FTO or on glass plate either by using doctor blade or spin coating method followed by annealing. After sensitizing it we are carrying out thin film photophysical studies. For investigation of solution state photophysical properties between the sensitizer and the nanoxide it is logic to use the same material i.e. with binder. It should be the actual condition. Am I right? Please give me your suggestions.

    Hamida Mohammed Bakr Darwish · King Abdulaziz University

    Yu can try and see the results. I think the best way to do experiment.

  • Ali Bakly added an answer:
    Is there any method to find the thickness of a thin film using UV-VIS-NIR transmission spectra (From the undulation obtained)?
    I need to find the the thickness of the films to know the other things.
    Ali Bakly · The University of Manchester

    Cheers, really all of above were in non-ill conditions

  • Zbyněk Večeřa added an answer:
    Any suggestions on the identification of nanoparticles in organs?

    At this time we are dealing with problem of identification of nanoparticles of CdO, PbO, MnO.Mn2O3 and TiO2 in mice organs and on erythrocytes (acute inhalation process (72 hours) and chronic inhalation experiment (60 and 90 days). From chemical analyses we know concentration of above mentioned elements, we have the TEM, STEM of "organs" where we can see objects "above mentioned nanopasticles". When we compare STEM, TEM control sample of mices´organs with organs the mice undergoes inhalation procedure at two levels (high concentration ca 10x6 particles/cm2 and low concentration 10x5 particles/cm2 in inhalation air)we can clearly see the difference in amount or "nanoparticles). But our STEM Edx was not able to identify the composition of nanoparticles, mainly if the elements are Cd, Pd, Mn or Ti.
    Do somebody to know the solution? If yes, there is possibility to do this procedure at some of this workplace and under which provision. We are ready to
    deliver samples of organs: control, "low" concentration and "high" in condition after TEM procedure.

    Zbyněk Večeřa · Academy of Sciences of the Czech Republic

    Oldrich

    thank for your answer and questions. I am going to phone you.

                                                                    Zbyněk

  • Vimal Patel added an answer:
    How to avoid powder formation during thin film deposition by Spray Pyrolysis?

    I am depositing pure metal oxide thin films by spray pyrolysis. I am getting good quality films. Whenever I am  trying with the doped metal oxides deposition with the same optimized conditions(distance between nozzle and substrates, molarity, solvents,quantity, temperature, air pressure and solution flow rate), films are not uniform. It is observed that after very thin deposition, powders are forming and it is in turn avoiding the deposition further. How shall I come out of this problem? What might be the effect of ultrasonic cleaning of thin films after deposition? Will it creates any defects in material and films?

    Vimal Patel · Gujarat University

    Reduce the temperature by controller or ultrasonic cleaning will help u. If u decrease temperature may possible change in phase formation.

  • Daniela Gogova added an answer:
    How accurate the EDX analysis can be in the case of nano sized precipitates of Nb with 10wt%Zr and 5wt%Fe in zirconium matrix containing 0.3wt%Nb?

    In so called fully-transformed by prolonged heat treatment below-near 580oC zirconium with 2.5wt%Nb-0.1wt%Fe alloy the Nb particles precipitate with the expected concentration of 10wt%Zr and 5wt%Fe. The particles are between 100 nm and 5 nm in size and zirconium matrix contains 0.3wt%Nb and no Fe. Is it possible to determine the concentration of Nb and Fe in such particles by EDX in analytical electron microscope? What the accuracy can be for particles having 100 nm size compared to particles of 5 nm size? How many particles one should analyze to obtain good representation of such precipitates in the alloy? What corrections are absolutely necessary in the analysis of EDX spectra in such system?

    Daniela Gogova · Central Lab of Solar Energy and New Energy Sources at the Bulgarian Academy of Sciences

    I agree with Daniele.

    In TEM microscopwill be easier

    D.

  • Oleg Anokhin added an answer:
    Why the Color of TiO2 nanotube arrays which I tried to fabricate via anodic oxidation is not white ( but blue, purple,..) ?

    I followed  published papers in  high impact factor Journals to fabricate TiO2 nanotube arrays but the color of the formed films was not white. The white color does not appear only if the  film get etching and then the powder start falls down

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  • Don Wilson added an answer:
    Reliable protocol for mercapo-silanes on glass?
    I am trying to bind gold nanoparticles to functionalized glass surfaces (optical fibers in particular) and the simple protocol I use works GREAT with 3-aminopropyltrimethoxysilanes, but fails regularly with 3-mercaptapropyltrimethoxysilane! The protocol is as follows:

    Clean fibers in pirhana (30min)
    Rinse with anhydrous ethanol.
    Immerse in anhydrous ethanol, add MPTMS/APTMS at 1% by volume for 1 hour.
    Remove and rinse with ethanol.
    Store fibers in ethanol until use.

    The weird part is I've had at least one trial where the MPTMS worked great. (I evaluate the efficacy by monitoring nanoparticles depositing on my fibers in realtime with UV-Vis). I am amenable to any suggestions and really have no idea why this protocol worked really great once, but mostly fails. I have tweaked most parameters such as immersion times, heating vs. non-heating etc.

    It's really confusing to me why this doesn't work since the only difference in these molecules is the headgroup.
    Don Wilson · Zorbtech Environmental Solutions

    try ....3-trimethoxysilpropyl dietthylene tiamine   TMSPETA

  • Moaz M Altarawneh added an answer:
    How can I remove the offset resistance of superconducting sample?

    I measured superconducting film sample by PPMS with DC four point method.
    (Input current and pick-up voltage)

    But always there is some non-zero resistance after transition happen.
    This non-zero voltage difference is removed when I turn-off current source.

    Anybody can give me a answer for this problem?
    Should I need AC measurement to get correct measurement?

    Moaz M Altarawneh · Mu’tah University

    If not interested in absolute values use Tunnel Diode Oscillator for mapping Hc2.

  • Ramachandran A V added an answer:
    How can I extract the values of data plotted in a graph which is available in pdf form?
    .
    Ramachandran A V · SASTRA University

    You can take screenshot of the Graph plotted and feed it as a image to Origin (or any other plot digitizer).

  • Pritam Ghosh added an answer:
    Are there any methods that could be used to measure the state of Fe/Fe3C during the CNT synthesis process? Is XPS suitable for this?

    To measure the state of Fe/Fe3C during the CNT synthesis process, can we just use XRD instead of XPS?

    Pritam Ghosh · Central Mechanical Engineering Research Institute and Jadavpur University

    XPS can be applicable easily,,,,

    PG

  • Zacharias G. Fthenakis added an answer:
    How can I simulate the folded layer of graphene ?

    Has anyone done that work? Which kind of software can do that job? Crystalmaker or ? See appendix for reference file. Thank you.

    Zacharias G. Fthenakis · Foundation for Research and Technology - Hellas

    You can use classic potentials, but for the interactions between graphene sheets you need a Van der Waals like potential. I do not know what exactly you want to do, but maybe you can distinguish in plane (strong) and out of plane (Van der Waals) interactions.

  • Martin Joseph added an answer:
    How can I use Beer-Lambert’s law for film thickness determination on glass?

    I have a copper film (Metal or oxide or mix) on a glass substrate. I measure transmission, reflection and I want to determine the film thickness.
    How I can do this with the Beer-Lambert’s law, or other?

    Martin Joseph · Christ College of Engineering & Technology

    use airwedge or michelson interference method to find the thickness of the coated film. or take TEM (CROSS SECTIONALLY.)

  • Fenglong Wang added an answer:
    How to make a uniform thin film with titanium dioxide nanoparticles with size around 30 nm? Which solvent and surfactant should I choose?

    I want to make titanium dioxide thin films for the sum frequency generation measurement with nanoparticles ca. 30 nm. What method should I choose? What solvent and surfactant should I use to get the uniform dispersion? Thanks guys. I need a uniform thin film.

    Fenglong Wang · University of New South Wales

    OK, thanks Rajesh and Luis, I will try the method you suggested above.

  • Amipara Manilal D added an answer:
    Is directivity and beam width the same for different unit cell (shape) metamaterial slabs having the same negative refractive index ?

    Suppose we have three different kind of negative refractive index metamaterial slab having different unit cell shape but all three have same refractive index. What would be directivity and beamwidth of all three metamaterial slab? Are they same or different because of different unit cell shape ?l

    Amipara Manilal D · Balaji Institute of Engineering & technology, Junagadh

    There is no direct relationship between numerical value of refractive index and beamwidth/directivioty. Directivity or beam width depends upon the current distribution in a slab.

  • Elena S. Davydova added an answer:
    How explain the oxygen Reduction Reaction in Pd nanoparticles electrodeposited on graphite?

    it is easier to reduce oxygen to produce the oxygen peroxide with palladium nanoparticles  ???
    taking into account that I want to form large amount of hydrogen peroxide in my experience on graphite electrode modified by palladium nanoparticles.
    thank you

    Elena S. Davydova · Russian Academy of Sciences

    Why cannot you just add H2O2 to your solution?

  • Soraya Sadeghi added an answer:
    How could I characterize the conductivity of the films produced by electrospining?

    How could I characterize the conductivity of the films produced by electrospining ? I prepare a polymeric solution , use different additives that increase the conductivity of solution ,put the prepared solution on stirrer and then use this solution in electrospinnig device . I use the hole effect test but the films show the same conductivity even the pure one it was 10 ^(7-) S/cm . I use another test of power supply and ameter . This test show no current and an open circuit sign appears.Is there another test or there is a mistake I dont notice? may I do some thing to know the conductivity ? I wish you help me....with my best regards.

    Soraya Sadeghi · Iran Polymer and Petrochemical Institute

    If the polymer that you used is a conductive polymer you can have conductivity through your unwoven mat. Besides, you used the additives to increase the conductivity of the polymer solution for better electrospinning and after that when solvent was evaporated, you may have not conductivity at all, if the polymer is not conductive. One way to measure the conductivity of a film is using AFM in contact mode. By using a conducting cantilever,  current can be passed through the tip to probe the electrical conductivity or transport of the underlying surface.

  • Kenneth M Towe added an answer:
    What is the difference between crystallite size, grain size, and particle size?
    How can we measure these sizes?
  • Ranjit Patil added an answer:
    Why is etch Ni rate so slow?

    I have 20nm Nickel evaporated on SiO2 layer.

    TFB was used for wet etch. According to its data sheet, a 25 A etch rate should be achieved, which means an etch time of 40 second.

    However, after 10 mins my shiny Nickel layer is still there.

    I also tried concentrated Nitric acid. After around ten minutes, it still doesn't work.

    What is wrong?

    Ranjit Patil · National Dong Hwa University

    I agree with Yuriy and just want to add little more details.

    It is true that, Ni is easy to get oxidize in the atmosphere also formation of hydroxide layer takes place if it is exposed to atm. air. I suggest you to examine the sample by XPS before etching to make sure that you still have film of Ni.

    FYI NiO is highly stable in the atmosphere and can withstand even in a corrosive atmosphere for a long period of time.

  • Jeffrey S. Meth added an answer:
    What is the grams per solution volume required to coat PEG in a spin coater?

    I try to make a thin film of coating PEG solution on glass substrate, but the resulted thin film contains many spots and unordered. Can anyone suggest to me the quantity of PEG that added to water to be suitable as thin film?   

    Jeffrey S. Meth · Dupont

    Karar,

    I would advise you with a few things:

    1) Yonkowski and Soane, Journal of Applied Physics, 72, 725 (1992) is a very good analysis of spin coating. 

    2)  When you spin coat, the first thing that happens is most of the solution flies off the edge, and what remains is a thin wet layer on the substrate.  That is the first stage.  In the second stage, that wet layer dries down.  The thickness of the wet layer at the end of stage one depends on the solution viscosity.  So you need to adjust the weight percent loading in conjunction with the molecular weight of the PEG to get to the desired thickness.

    3)  Your PEG should be dissolved for a few days prior to spin coating.  Apply the solution to the substrate via a syringe, with a syringe filter attached to the end.  A one micron filter will trap most of the dust.  Use a second pipette to suck back up any bubbles that are on the surface of the solution when it is on the substrate.  

    4) You will not avoid the Maragoni defect in the center of the plate.  Sometimes annealing in an oven (for PEG, set the oven to 80 C) will help.

    Good luck!

    Jeff

  • Can I use glass as substrate to observe SEM sample?
    I want to know if glass substrate can be used to get clear photographs in SEM. I know silicon has better conductivity, but my sample was prepared on a glass substrate. Thank you.
    Chandrakanth Chandrasekharan · National Institute for Interdisciplinary Science and Technology

    Most of the SEM sample preparation and operational parameters are discussed above in detail.  However, in the unavoidable situation  of gold sputter coating on a glass substrate where the sample is attached, gentle filing of the glass edges forming an obtuse angle with the sample holder surface will help in forming a continuous coated layer improving the conductivity and image resolution.

  • Mostafa Eidiani added an answer:
    Is there any theoretical proof of the field emission property of monolayer planar graphene sheets?
    Is there any paper giving theoretical proof on field emission from a planar graphene sheet?
    Mostafa Eidiani · Khorasan Institute of Higher Education

    Hi

    I find this paper:

    http://arxiv.org/pdf/cond-mat/0702595

  • Bouhafs Djoudi added an answer:
    How does the substrate affect the refractive index of metal thin film?

    I have deposited silver thin films of glass and TiO2 surfaces.

    The structures are Ag/glass and Ag/TiO2/Glass. The silver thickness is ~20 nm. Why is there a difference in the refractive index?

    Any refrences

    Bouhafs Djoudi · Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE)

    Ag refractive index of the 20 nm layer has the same values if the deposition conditions are the same in both structures: Ag/Glass and Ag/TiO2/Glass. So the source of this difference is inherent to the physical model of ellipsometry based on the interference and the multi-reflection of the light at the interfaces. When we use transparent substrates instead of the opaque one’s, a marge of error on calculating n, k from ellipsometric parameters  and  occur generally. In your experiment this error is amplified by the quasi transparent Ag deposited layer (20 nm) on a transparent substrate (Glass). In conclusion, I suggest depositing the Ag 20 nm in the same conditions on a thick silicon substrate (300-400 µm) and measuring n & k by ellipsometry, which give you exact values of n&k. Otherwise, if you continue to ellipsometric measures on your structures, you obtain the same results with different values essentially due to the transparency of your very thin Ag layer on a transparent substrate and the optical technique (Ellipsometer) is very sensitive to this parameter source generating an error percentage in optical measurements of n, k.

  • Larry Kwesi Sarpong added an answer:
    How to functionalize CNT using concentrated sulfuric acid and nitric acid?
    Currently I'm using concentrated H2SO4:HNO3=3:1 to treat the CNT. Refluxing it for 5h, at the end of my work I found that my CNT had reduced greatly in weight. From my reading I found out that the CNT might had been degraded due to the concentrated acids. What is the best way to deal with this if I were to use sulphuric and nitric acid?

    The second problem I faced was to separate the mixture of acids and cnt as the filters being chipped by the acid, the alternative way I used to separate by centrifuging the mixture. Any suggestions for that?

    Thank you
  • Ajeet Kumar added an answer:
    What is the minimum value of electric field required to pole a 4micron thick PVDF-TrFE film?

    I am using a home made poling system which has a voltage source of 5KV. XRD results are same for both poled and un-poled samples

    Ajeet Kumar · Defence Research and Development Organisation

    First perform the P-E measurement to calculate the coercive field (Ec) of your sample. Based on coercive field value, you can poled your sample.

    In my opinion for 4 micron thick film, you may get poling voltage less than 5 kV (from coercive field value). If it is more than 5kV than try to reduce the thickness of films.

  • Pradip Kumar Dey added an answer:
    What could be the possible reason if some material does not stick on glass and Silicon substrates?

    I am coating my gel(Metal oxides) on glass and silicon substrates by dip coating or by spin coating but it is not sticking on substrates properly what could be the possible reason for it?

    Pradip Kumar Dey · IIT Kharagpur

    Either the surface is contaminated or contain any foreign materials. To overcome this issue clean either glass of silicon in Piranha solution (H2O2 and H2SO4) @ 20 min and dry in oven for 30 min @ 150 Deg. Cent. For glass substrate treat in oxygen plasma for 30 sec before deposition to promote adhesion and for silicon grow a thin oxide layer and then deposit any material.

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