{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 6 : Imperfections, Defects and Dislocations in Solids" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 6.1 pageno : 125" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "# Variables\n", "na = 6.023*10**23;\t\t\t#Avagadro's no.\n", "p = 3170.;\t \t\t#density in kg/m**3\n", "\n", "# Calculations\n", "mw = 7.9*10**-2;\t\t\t#molecular weight of CaF2\n", "nl = na*p/mw;\t\t\t #calcium ions/cubic m\n", "ni = 2.*nl;\t\t\t # /cubic m\n", "t = 1300.;\t \t\t#in K\n", "ef = 2.7*1.6*10**-19.;\t\t\t#energy of formation of one frenkel defect\n", "k = 1.38*10**-23;\t\t\t#boltzmann constant\n", "nf = math.sqrt(nl*ni)*math.exp(-ef/(2*k*t));\t\t\t#in /cubic m\n", "\n", "\n", "# Results\n", "print \"No. of Frenkel defect per unit volume of Calcium Fluoride (in /m**3) = %.2e /m**3\"%nf\n", "\n", "# note: Answers may vary because of rouding error." ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "No. of Frenkel defect per unit volume of Calcium Fluoride (in /m**3) = 2.02e+23 /m**3\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 6.2 pageno : 127" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "# Variables\n", "r = 8.314;\t\t\t# J/mol K\n", "t1 = 300.;\t\t\t#in K\n", "t2 = 1000.;\t\t\t#in K\n", "\n", "# Calculations\n", "ent = 168*10**3; \t\t\t#enthalpy of formation of vacancy in J/mol\n", "x1 = math.exp(-ent/(r*t1));\t\t\t#x1 = n/Na\n", "x2 = math.exp(-ent/(r*t2));\t\t\t#x2 = n/Na\n", "rt = x1/x2; \t\t\t#ratio \n", "\n", "# Results\n", "print \"Ratio of no. of vacancies = %.2e\"%rt\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Ratio of no. of vacancies = 3.34e-21\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 6.3 page no : 132" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Calculations\n", "# for 1/6[121] dislocation\n", "a1 = 1./6 * 1 # x - component\n", "b1 = 1./6 * 2 # y - component\n", "c1 = 1./6 * 1 # z - component\n", "\n", "# for 1/6[211] dislocation\n", "a2 = 1./6 * 2 # x - component\n", "b2 = 1./6 * 1 # y - component\n", "c2 = 1./6 * -1 # z - component\n", "\n", "a = a1 + a2 # x - component\n", "b = b1 + b2 # y - component\n", "c = c1 + c2 # z - component\n", "\n", "# Results\n", "print \"X-component a = %.1f\"%a\n", "print \"Y-component b = %.1f\"%b\n", "print \"Z-component c = %.1f\"%c\n", "\n", "print \"Thus, [abc] = [%.1f %.1f %.1f] = 1/2[110]\"%(a,b,c)\n", "print \"Hence, 1/6[121] + 1/6[211] -> 1/2[110] proved\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "X-component a = 0.5\n", "Y-component b = 0.5\n", "Z-component c = 0.0\n", "Thus, [abc] = [0.5 0.5 0.0] = 1/2[110]\n", "Hence, 1/6[121] + 1/6[211] -> 1/2[110] proved\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 6.4 pageno : 136" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "# Variables\n", "v = 0.31; \t\t\t#poisson's ratio\n", "bv = .25*10**-9;\t\t\t#burger's vector in m\n", "ri = 1.1*10**-9;\t\t\t#in m\n", "\n", "# Calculations\n", "r0 = 10.**5*bv;\t \t\t#in m\n", "sm = 45.*10**9;\t\t \t#shear modulous in n/sqm\n", "gb_2 = sm*bv**2;\n", "u_ed = (gb_2/(4*3.14*(1-v)))*math.log(r0/ri);\n", "u_sd = (gb_2/(4*3.14))*math.log(r0/ri);\n", "r = u_ed/u_sd;\t\t\t#ratio\n", "\n", "# Results\n", "print \"Elastic Strain Energy of Edge dislocation (in J/m) = %.2e J/m\"%u_ed\n", "print \"Elastic Strain Energy of Screw dislocation (in J/m) = %.2e J/m\"%u_sd\n", "print \"Ratio of energies of edge dislocation over screw dislocation = %.2f\"%r\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Elastic Strain Energy of Edge dislocation (in J/m) = 3.26e-09 J/m\n", "Elastic Strain Energy of Screw dislocation (in J/m) = 2.25e-09 J/m\n", "Ratio of energies of edge dislocation over screw dislocation = 1.45\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 6.5 pageno : 139" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "r = 1.7*10**-10;\t\t\t#atomic radius in m\n", "n1 = 10.**-3; \t\t\t#1mm = 10**-3m\n", "\n", "# Calculations\n", "a = 2*r;\t\t \t#in m\n", "n = n1/a;\n", "ed = 2.*10**-6; \t\t\t#edge dislocation in m\n", "ns = ed/a;\n", "nv = n*ns;\n", "\n", "# Results\n", "print \"Total no. of created vacancies = %.2e\"%nv\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Total no. of created vacancies = 1.73e+10\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 6.6 pageno : 142" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "# Variables\n", "c1 = 3.61 # lattice parameter of copper\n", "c2 = 44 # shear modulus of copper\n", "\n", "# Calculations\n", "b = c1*math.sqrt(1**2 + 1**2 + 0**2)/2.\n", "U = c2*b**2 * 10**9 * 10**-20/2.\n", "\n", "# Results\n", "print \"The magnitude of the Burgers vector : %.3f A\"%b\n", "print \"LIne energy of dislocation U : %.3e J/m\"%U" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The magnitude of the Burgers vector : 2.553 A\n", "LIne energy of dislocation U : 1.434e-09 J/m\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 6.7 pageno : 144" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "# Variables\n", "a = 3.84 # lattice constant\n", "h = 1\n", "k = 1\n", "l = 0\n", "\n", "# calculations\n", "b = a*math.sqrt(h**2 + k**2 + l**2)/2.\n", "h1 = b/math.tan(math.radians(1))\n", "h3 = b/math.tan(math.radians(3))\n", "\n", "# Results\n", "print \"b = %.3f A\"%b\n", "print \"Spacing between dislocaitons in a low angle tilt boundary in iridium\"\n", "print \"When,\"\n", "print \"Angle of tilts 1 = %.2f A\"%h1\n", "print \"Angle of tilts 3 = %.2f A\"%h3" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "b = 2.715 A\n", "Spacing between dislocaitons in a low angle tilt boundary in iridium\n", "When,\n", "Angle of tilts 1 = 155.56 A\n", "Angle of tilts 3 = 51.81 A\n" ] } ], "prompt_number": 1 } ], "metadata": {} } ] }