A beam of X-ray diffraction (XRD) with a CuKa radiation of wavelength, λ = 1.541 Å, falls on a powder of three samples (A, B and C) which crystallized in the following crystal structure: sample A: body center cubic (BCC) with lattice parameter a = 4 Å; sample B: tetragonal, with lattice parameters a = b = 4 Å and c = 6 Å and sample C: orthorhombic, with lattice parameters a = 4 Å, b = 6Å and c = 8 Å. 1. For the first order Bragg diffraction, which of the three sample will give the smallest Bragg angle on the plan (111)? 2. Explain clearly with some calculations, if there will be higher order reflections on the plan (111) for the three samples.

A beam of X-ray diffraction (XRD) with a CuKa radiation of wavelength, λ = 1.541 Å, falls on a powder of three samples (A, B and C) which crystallized in the following crystal structure: sample A: body center cubic (BCC) with lattice parameter a = 4 Å; sample B: tetragonal, with lattice parameters a = b = 4 Å and c = 6 Å and sample C: orthorhombic, with lattice parameters a = 4 Å, b = 6Å and c = 8 Å. 1. For the first order Bragg diffraction, which of the three sample will give the smallest Bragg angle on the plan (111)? 2. Explain clearly with some calculations, if there will be higher order reflections on the plan (111) for the three samples.