In practice this is achieved by using a polycrystalline sample or powder, grains of which are still enormous on the atomic scale 2θ of diffraction for a plane with d-spacing d(hkl) λ/2 is the smallest size that can be measured At small angle d goes to ∞ The function depends on θ not 2θ. This analysis uses x-ray diffraction (debye-scherrer method) In this experiment, the diffraction patterns of x-rays of known wavelengths will be analysed to determine the lattice constant for the diffracting crys