Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium


Finding the lattice constant for a zincblende (modified fcc) crystal ...

Posted on 2006-03-31
Medium Priority
Last Modified: 2008-03-17

I want to know how you would find the lattice constant (edge length) for a crystal unit cell if it is a zincblende, in effect, composed of atoms of two different radii. In this case (a homework problem I'm stuck on) the atoms are In and SB, but generally speaking ... isn't zincblende essentially the same as a diamond structure? How do the differing radii change the standard formulas, ie, the ones I actually know?
Question by:princess_of_reason
  • 2
LVL 11

Accepted Solution

bingie earned 2000 total points
ID: 16352027
What is the "touching direction" of Zinc Blend, i.e. the direction of the atoms where the most "touching" occurs.

For instance in FCC the touching direction would be accross the face diagional where a=root(2) x a and in BCC the touching direction is the body diagional where a = root(3) x a. Here a is the edge length.

And yes, ZnS does have 2 different sized ions ( 14 Zinc and 4 Sulfur ) but the sulfur are arranged in a specific tetrahedral pattern inside the FCC structure. And yes, it is exactly like the diamond cubic structure, just with sulfur instead of zinc in the center of the cube.

So, I would use a corner atom and one at the (1/4,1/4,1/4) position (starting up the body diagional) to get a length = ( body diagional ) / 4. Then go from there.


Author Comment

ID: 16408231
With your guidance, I've worked it out. Thank you! (And I apologise for taking so long to respond.)
LVL 11

Expert Comment

ID: 16408268
No problem!

Glad i could help.


Featured Post

Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction On a scale of 1 to 10, how would you rate our Product? Many of us have answered that question time and time again. But only a few of us have had the pleasure of receiving a stack of the filled out surveys and being asked to do somethi…
This article provides a brief introduction to tissue engineering, the process by which organs can be grown artificially. It covers the problems with organ transplants, the tissue engineering process, and the current successes and problems of the tec…
This is a video describing the growing solar energy use in Utah. This is a topic that greatly interests me and so I decided to produce a video about it.
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…
Suggested Courses

581 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question