Electrons accelerated by potential V are diffracted from a crystal. If d = 1Å and i = 30°, V should be about (h = 6.6 × 10 –34 Js, me = 9.1 × 10–31kg, e = 1.6 × 10 –19C)
Wave property of electrons implies that they will show diffraction effects. Davisson and Germer demonstrated this by diffracting electrons from crystals. The law governing the diffraction from a crystal is obtained by requiring that electron waves reflected from the planes of atoms in a crystal interfere constructively (see figure).
(a) 1000V
(b) 2000V
(c) 50V
(d) 500V.
