Homework # 2Chapter 2 KittelProb # 1, 2Phys 175ADr. Ray KwokSJSUConsider a plane (hkl) in a crystal latticea1a2a3ABCProb # 1 – Interplanar SeparationJohn Anzaldo(a) Prove that that the reciprocal lattice vector G = hb1+ kb2+ lb3is perpendicular to this plane We know that plane (hkl) gives axis intersections at the reciprocals to the values of the plane index, giving us intersections at (1/h,0,0), (0,1/k,0) and (0,0,1/l) labeled points A, B and C. If the vectors made by the connection of these points are perpendicular to G, their dot product will be zero.Prove that that the reciprocal lattice vector G = hb1+ kb2+ lb3is perpendicular to this planeAB= AC= CB= for an a1, a2, a3basisG•AB=Similarly for AC and BC, hence demonstration of perpendicularity.(b) Prove that the distance between two adjacent parallel planes of the lattice is If you scale the intercepts by integer values you will find that there is always a plane repeated from a perfectly translated origin (i.e. T=u1a1+u2a2+u3a3 , where uiis an integer) The closest distance between a point and a plane iswhere is the unit normal to the plane and a vector from some point to the plane. For our purposes we will use point (0,0,0) and a point on the plane (1/h,0,0) to find vector .Prove that the distance between two adjacent parallel planes of the lattice is Vector = , and = This gives which proves the relationship in question.(c) Show for a simple cubic lattice that For a simple cubic we know for i≠j, and Usingwe find thatwhich gives , which yieldsProb # 2 – Hexagonal Space LatticeDaniel WolpertGiven: Primitive translation vectors of the hexagonal space latticea1= (3½a/2)ẋ + (a/2)ẏa2= -(3½a/2)ẋ + (a/2)ẏa3= cẑA) Find the Volume. Triple product: |a1· a2x a3| =cẑ000(a/2)-(3½a/2)0(a/2)(3½a/2)= 3½/2 a2cB) Find the primitive translations of the reciprocal latticeB1= 2π (a2x a3)/ V B2= 2π (a3x a1)/ V B3= 2π (a1x a2)/ V 2πcẑ000(a/2)-(3½a/2)ẑẏẋ= 2π/a3½ẋ + 2π/a ẏ0(a/2)(3½a/2)cẑ00ẑẏẋ2π 2π0(a/2)(3½a/2)cẑ00ẑẏẋ= -2π/a3½ẋ + 2π/a ẏ = 2π/c ẑSketch the first Brillouin zone of the hexagonal space
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