Search results

  1. O

    Splitting of Eu characteristic L gamma radiation in EDX analysis?

    Haven't been able to find the answer anywhere IRL yet, so I thought I'd see if someone in the PhysicsForums could help me with this one. When doing SEM/EDS (EDX/EDXS) (~equivalent to x-ray fluorescence) analysis it looks as if my europium containing samples contain copper as well, which'd...
  2. O

    Dodecahedral metal coordination?

    Is it true that there should be two distances from a dodecahedrally coordinated cation to the two types of coordinating atoms? When I calculate what the octahedron should look like assuming that all anion-anion distances are equal I will get two different cation-anion distances: if all...
  3. O

    Teflon and alkoxides?

    Hi! I heard from somebody that teflon might react with some alkoxides, and that this is actually what DuPont uses in some cases to make the teflon coatings stick to cookingware or whatever is coated in these specific cases. This bothers me since I have a cuvette with a teflon stopper...
  4. O

    Term symbols & degeneracy

    Hi! I've finally made some effort to understand spectroscopic term symbols (^{2S+1}L_J) and after having thought a few times that I'd understood but then running into trouble again, now I'm fairly convinced that I got it right. But some things bother me though. Apparently I was locked too...
  5. O

    Silicon inert?

    Hi! Is silicon inert? i.e. can I clean it from deposited films with e.g. HNO3 and H2SO4 without etching the silicon itself? What about amorphous carbon?
  6. O

    Stuff that attacks materials

    Hi! Does anyone know a good reference literature or internet resource regarding what materials are compatible with which acids, solvents etcetera? I'm no good at this at all. I had e.g. no idea that ammonia attacks aluminium. Are silicon and amorphous carbon attacked by anything or are they...
  7. O

    Chloroform and metals

    Chloroform is said to react violently with both metals (Al, Na, Li, Mg, K, Fe, Zn) and e.g. sodium methoxide (CH3ONa). Does anyone know more about this? What happens? Formation of e.g. CCl3Na with release of H2? Or CHCl2Na+NaCl? And how about reaction with alkoxides? Does chloroform react...
  8. O

    Tetrahedrally adapted d-orbitals?

    Does anyone have a link to a picture of the shapes of tetrahedrally adapted atomic d-orbitals? Aren't the familiar d(z2), d(x2-y2), d(xz), d(xy) and d(yz) orbitals just one of several possible sets of atomic d-orbital shapes? Or have I misunderstood this point? I would like to rationalise why...
  9. O

    Tetrahedrally adapted metal d-orbitals?

    Usually the d-orbitals are displayed adapted to octahedral symmetry. But as I understand it, one could just as well picture degenerate representations of the same orbitals in other high symmetries. Does anyone have a link to a page containing pictures of the d-orbitals in the form adapted to...
  10. O

    How to use and interpret C NMR?

    Could someone explain to me how to use and interpret C NMR? For proton NMR there are (fairly) simple coupling rules from which to deduce that there, e.g., are two protons on a carbon next to a CH3 group. Is there anything alike for multinuclear NMR? Titanium NMR would be fun to do also, or won't...
  11. O

    Reaction of silver and sulphur

    I was thinking about the reaction of silver and sulphur. I've read that when copper is oxidised by oxygen, after the formation of the first film of Cu2O, it is actually the copper atoms diffusing out of the bulk copper through the Cu2O layer to the air, where they are oxidised. Does...
Top