Unformatted text preview: 36. Each Arsenic atom is connected (by covalent bonding) to four Gallium atoms, and each Gallium atom is similarly connected to four Arsenic atoms. The “depth” of their very non-trivial lattice structure is, of course, not evident in a ﬂattened-out representation such as shown for Silicon in Fig. 42-9. Still we try to convey some sense of this (in the [1 , , 0] view shown below – for those who might be familiar with Miller indices) by using letters to indicate the depth: A for the closest atoms (to the observer), b for the next layer deep, C for further into the page, d for the last layer seen, and E (not shown) for the atoms that are at the deepest layer (and are behind the A’s) needed for our description of the structure. The capital letters are used for the Gallium atoms, and the small letters for the Arsenic. Consider the Arsenic atom (with the letter b) near the upper left; it has covalent bonds with the two A’s and the two C’s near it. Now consider the Arsenic atom (with the letter d) near the upper right; it has covalenttwo C’s near it....
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This note was uploaded on 11/12/2011 for the course PHYS 2001 taught by Professor Sprunger during the Fall '08 term at LSU.
- Fall '08