Science topics: Transition Elements
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Transition Elements - Science topic

Elements with partially filled d orbitals. They constitute groups 3-12 of the periodic table of elements.
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Pb^2+ exist in group1 as a chloride(PbCl) with HCl as its precipitating agent while it exist in group 2 as sulphide (PbS) with H2S as its precipitating agent.
Can Pb be confirmed in both of them ?
I confirmed Pb in group 1 which made me stop half way of confirming for its presence in group 2. While we were doing the group separation for group 2, we passed it through H2S at the kipps apparatus which upon reaction with the gas turned our solution to black ppt., which we filtered to obtain a black residue which I suspect to be PbS. However for group 2 I discovered that CuS,HgS,Bi2S3 are also black in colour. Time wasn't on my side to run the confirmatory test. So is it fine to just report the one I confirmed which is group 1.
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I just started to study about Mott’s Formalism and as I was going through some prerequisite material for Variable-Range Hopping Conduction I read the following paragraph,
" Theories on non-defective non-doped semiconductors show that the Fermi level is positioned around mid-gap to obey the condition of charge neutrality in the material. In the case of band conduction in SiOx this would lead to an increase in activation energy with increasing x, from around 0.9 eV in a-Si up to around 1.5 eV for suboxides with x ≈ 1.5. Indeed, an increase in activation energy has been observed in several studies on the conduction of different silicon suboxides. In these studies the x dependence of the (room temper- ature) resistivity of SiOx is easily explained in terms of an increased activation energy within a band conduction model. "
Can someone please explain how does the band gap increase when x increases in Silicon Suboxides?
PFA the document I am referring to.
Thanks in advance!
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If the conduction is due to the intrinsic carriers , then
ni^2 is proportional to exp^-Eg/kT,
in case of intrinsic material n=p=ni
it follows that ni is proportional to exp^-Eg/ 2kT= exp ^- Ea/2kT,
The activation energy Ea in this case= Eg/2
Consequently as the energy gap increases the the activation energy increases.
It is so when the oxygen content increases the bond becomes stronger and the energy gap increases and consequently the activation energy.
This is the explanation of the statement in the question.
Best wishes
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I would like to know the different ways to combine M-Se ( where M can be Cu,Co,Fe,Pd,Ru) with MXene (Ti3C2Tx). I recently happen to come across one method which is hydrothermal synthesis using autoclave, likewise are there any other different methods or is hydrothermal synthesis the only option for the given objective?
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Dear Lokesh Murali,
The following review article seems to provide a good sort of information.
Recent progress in layered transition metal carbides and/or nitrides (MXenes) and their composites: synthesis and applications, (2017), Journal of Materials Chemistry A
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Usually, the metals are Ti, Cr, Fe, Ni; and their alloys. They do form protective films in moderate corrosive environment, and their films dissolve away in very strong corrosive environment. But why not all metal behave so? What causes their protective films to be retained?
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Dear Sumit,
This is due to close electron affinity and potential value orderly arranged in electrochemical series. Very few elements are closed in their potential values. Values of Co and Ni are having -0.28 and -0.25.
Ashish
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Nickel is one of transition element,and its rarely present in diet,Nickel is a mineral. It is found in several foods including nuts, dried beans and peas, soybeans, grains, and chocolate. The body needs nickel, but in very small amounts. Nickel is a common trace element in multiple vitamins.
Nickel is used for preventing nickel levels in the blood from getting too low (nickel deficiency). It is also used for low levels of healthy red blood cells (anemia) due to iron deficiency and treating weak and brittle bones (osteoporosis), but there is no good scientific evidence to support these uses. but nowdays its found some applications,so what are other use of element?
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There are three types of antiferromagnetism, namely A , C and G type. I want to perform DFT calculations with these types of antiferromagnetism using either Quantum Espresso or Wien2K codes in full inverse Heusler alloys with general formula X2YZ (X and Y being transition elements and Z being an sp element. The Xs are at (0,0,0) and (0.25,0.25,0.25), Y at (0.5,0.5,0.5) and Z at (0.75,0.750.75).
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I'm not quite sure what you're asking, but in general all you will need to do is to run the DFT calculation in "spin polarised" mode, and initialise the atomic spins to an appropriate AFM configuration. Depending on the code, there may be options to actually constrain the spins to a particular configuration; if not, you may be limited to studying stable and metastable AFM configurations (which might be fine, it depends what you want to study).
I should add that I don't use QE or Wien2K, I'm a CASTEP developer (http://www.castep.org), but I don't think there will be any fundamental differences in how the modelling is performed. Of course if you wanted to use CASTEP for the simulations I could give more specific advice.
All the best,
Phil Hasnip
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i recorded the spectrum of a transition metal complex, and get the wave length of the main characteristic absorption bands, ( at 600–620 and 500–520 nm ) , Now I need to know which absorption band is assigned for which electronic transition type ( 4T1g (F) → 4A2g (F) or 4T1g (F) → 4T2g (P) or 4T1g (F) → 4T1g (P) transitions or ........What............ )
Any suggestions how can I calculate / find that ???
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Hi,
You can use the Tanabe-Sugano diagram to calculate (theoretically) your desired transitions: See the link below
In addition, you can do DFT/TDDFT calculations to predict metal centered several d-d transition at 500-700 nm (for specific HOMOs to LUMOs).
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Usually, when PL analysis of transition metals and it's different dericatives has been carried out, we get a PL spectrum of it having multiple peaks excited by only one (excitation) wavelengh? Why it is so? and, what is the exact role of excitation wavelength?
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If you consider both absorption and radiation is involved when light interacts with matter, then you can think of Luminescence process be described as the inverse of absorption, inform of a radiative process created by the recombination of excited electrons (as supposed the non-radiative recombination processes leading to thermal effects). Therefore, one may observe transitions between band-edges (band-to-band transition) or in presence of impurities for doped semiconductors one may observe lines associated with transition from within the conduction band (donor states) and valence band (acceptor states). Most likely multiple lines observed in your experiment indicates transitions involving impurity states. The exact role of excitation wavelength is that to observe all possible excitations, the excitation wavelength should be shorter than the most energetic transition, otherwise some if not all transitions will be absent in the PL spectra. The following article shows that PL spectra of doped nanocrystal include emission peaks at higher wavelengths compared to the un-doped ZnS nanoparticles: https://www.sciencedirect.com/science/article/pii/S0749603615002499,
Also, the link below leads to a more general description of PL spectroscopy: https://www.sciencedirect.com/topics/chemistry/photoluminescence-spectroscopy
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in a pure batio3 transition temperature is increase on doping of transition element. plz help me to understand .
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hi....khagesh,....its structural transition ,i already mention that its doing of transition element like co, cr, Fe, Ni in batio3.
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I want to seek the opinions of experts in the field of environmental science. I intend to determine elemental contents of some freeze dried plant samples collected after an experiment. Since I want a non destructive method of determination of these elements, mostly transition elements. I am being sceptical about the use of XRF because I have been used to the use of conventional method of total digestion and analysis by either A AS or ICP MS. So, I want to hear opinion of people that have used XRF concerning the reliability and reproducibility of results. Is it better than normal conventional element analysis and how reliable are the results from XRF? Thank you all
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XRF is not better than normal conventional element analysis but much faster and enables you to analyze the elemental range from Na to the  transuranic elements. The d-block transition elements work very well with detection limits in the lower ppm range (based on dry matter).
How reliable are the results from XRF: The answer is quite simple, it depends very much on Your sample prep, a general answer is not possible. To have a start point I would recommend to start  with freeze-dried samples as loose powder and a fundamental parameter based XRF quantification. You could give some of Your samples to an XRF lab to test it if it fits Your needs, analyses are cheap.
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Hello all, could you tell me any chemicals that has similar reaction properties to Zero Valent Iron (ZVI) Fe0. it is transition element. and very reactive chemical ( catalyst. Thanks
i am think if i shall do comparative studies for environmental remediation and addictive in process engineering.
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Thank you sir.  is ZVI available on market? laboratory synthesis to it have only minimal yield.
thanks you so much Sir Kanhaiya  
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Can anybody tell me why there is a strong satellite peaks in photoelectron spectroscopy for transition and rare earth elements having unpaired number of electrons. But it does not observe for closed shell structure. As an example Cu+1 (d10) configuration does not have satellite peaks and Cu+2 (d9) having a strong satellite peaks. 
Thanks
Anupam
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Gupta and Sen speculated that if excited states were taken into account, "calculations will automatically and naturally also predict the so-called shake-up satellites" [1,2]. This statement was based on the expectation that the presence of the satellite is caused by “shake-up” event. i.e.  excitation of an unpaired 3d electron to a higher bound energy level (possibly 4s). This results in the kinetic energy of the 2p electron being reduced by the excitation energy of the unpaired 3d electron.
Thus. two peaks result, one for the 2p excitation and one for the combined effect of the 3d and 2p excitations. Due to the reduced kinetic energy. the satellite occurs at a higher apparent BE.
See these articles as a references
[1] Gupta RP, Sen SK. Phys. Rev. B. 1974; 10: 71.
[2]  Gupta RP, Sen SK. Phys. Rev. B. 1975; 12: 15
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How do I separate ions of transition metals: nickel, cobalt and manganese by precipitation (hydroxide and carbonate) from the leaching solution?
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 Pls. find a detailed procedure in a file attached herewith
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Has anyone the experience about the charge ordered system? e.g. La1-xSrxMnO3 or RNiO3 systems. For the long range order type, the MR~H curve will be symmetrical?
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I am not sure whether you can at all decide whether the charge ordering long range or short range just by MR-H curve. If my MR you mean magnetoresistance then it is a property which is blind to the correlation length of the charge ordering. The correlation length can only be decided by diffraction (X-ray, neutron or electron) measurements. One must scan the superlattice reflection corresponding to the charge ordering and measure its width. If the width is larger than the instrument resolution then you conclude that the correlation is finite and if the width is very then the ordering is short range. If the width is small and the instrument resolution is good then can conclude that the ordering is long range or at least the correlation length is quite large.
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Using Transition element for meshing in Abaqus heat transfer problem.
I want to use the transition element between coarse and fine meshed zone. Can any body tell me the steps? 
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Hi,
If your model is complex,then better you use hyper mesh for meshing your model.You can create transition element between coarse and fine mesh easily in Hypermesh.
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I am trying to optimize a transition state where there is two different bond breaking events.  It is a proton transfer reaction and a concerted mechanism. I have modeled a couple of transition states but none of them seems to give me the correct TS. I do not see any bond breaking/forming in any of the transition states I have modeled . Can anyone help me or give me some feedback? 
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Hello Oleg, 
I did calculate IRC, but my IRC only connects two points in the path. Also, I tried relaxed scan. I am using gaussian for this. Thank you 
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Magnetic susceptibility
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You can evaluate the susceptibility of organics using some theoretical method i.e consider it to be contributed by atomic susceptibilities of the atoms consisting the molecule. Than knowing that Cu is weakly diamagnetic and iron is ferromagnetic you can predict how they will afect the mag. susceptibility of initial compound.