3. (a) For a 200 kV electron beam, the wavelength is 0.0025 nm. Using the Rayleigh criteria, d = 0.61 x wavelength, calculate the wavelength limited resolution. (10 marks) (b) To obtain an interpretable high-resolution TEM image, the optimum condition is to take the image at Scherzer defocus: Af Sch=_1.2C.12. At this defocus, the point resolution is defined as rsch=0.66(C31/423/4). Assuming the spherical aberration coefficient Cs is 1mm and the accelerating voltage is 200kV (wavelength is 0.00251nm). Calculate the Scherzer defocus and the point resolution of this TEM. (10 marks) (c) Compare the wavelength limited resolution and the point resolution you calculated in (a), and explain what is the limiting factor of the resolution in a TEM. (10 marks)