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Homework Help: Planar concentration

  1. Sep 8, 2008 #1
    1. The problem statement, all variables and given/known data
    Niobium Nb has the BCC crystal with a lattice parameter of a= .3294 nm

    Find the planar concentrations of atoms per m^2 of the (100, (110) and (111) planes.

    The 100 plane has 1 atom on the plane (1/4 times 4)

    the 110 plane has 2 atoms on the plane and using pythagorean theorem the long side is a*sqrt(2)

    http://www.gly.uga.edu/schroeder/geol6550/111.jpeg [Broken]
    best pic I could find for the 111 plane
    Now for the last plane (111) this is what I did

    the area would be 1/2 base * height
    the base is [tex]a*\sqrt2[/tex] and

    pythagorean theorem to find the height is a^2 and half of the long side from plane (110) squared [tex]\sqrt{a^2+\frac{2a^2}4}=.4034nm[/tex]

    [tex]
    \frac12(.4034)10^{-9}(.3294)10^{-9}
    [/tex]
    Now how many atoms are on the plane? and are there mistakes in what I have done so far?

    And how many atoms would that (111) plane have in a FCC model?
    Answer would have number of atoms over area
    Thanks for the help
     
    Last edited by a moderator: May 3, 2017
  2. jcsd
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