6. Structure Factor for GaAs. GaAs (shown to the right) is a semiconductor that forms in the zincblende crystal structure, which looks similar to the diamond structure except that it has two different elements. a. Give the (hkl) indices for the 4 lowest (nonzero) first order diffraction angles you would expect for this structure. (Do not include second or higher orders of any of your peaks.) b. In reality, there will be angular effects that reduce the peak intensity with angle, but ignoring that, use the structure factor to show how the intensity of these peaks compare? You may assume atomic scattering factors of fGa and fAs for the two atoms. (This relates to the expected relative intensities of the peaks.) Show your work using Bragg's law to calculate the expected diffraction angles for the lowest 3 angles for GaAs if the wavelength of your x-ray source is 0.1542 nm.