{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 5: Crystal physics" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 5.1: determine_miller_indices.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "// chapter 5 , Example5 1 , pg 149\n", "//plane has intercepts a,2b,3c along the 3 crystal axes\n", "//lattice points in 3-d lattice are given by r=p*a+q*b+s*c\n", "//as p,q,r are the basic vectors the proportion of intercepts 1:2:3\n", "p=1\n", "q=2\n", "s=3 \n", "//therefore reciprocal\n", "r1=1/1\n", "r2=1/2\n", "r3=1/3\n", "//taking LCM\n", "v=int32([1,2,3])\n", "l=double(lcm(v))\n", "m1=(l*r1)\n", "m2=(l*r2)\n", "m3=(l*r3)\n", "printf('miler indices=')\n", "disp(m3,m2,m1)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 5.2: calculate_density_of_Si.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "// chapter 5 , Example5 2 , pg 150\n", "a=5.43*10^-8//lattice constant(in cm)\n", "M=28.1 //atomic weight (in g)\n", "n=8// number of atoms/cell (for Si)\n", "N=6.02*10^23 //Avogadro number\n", "C=n/a^3 //atomic concentration =(number of atoms/cell)/cell volume (in atoms/cm^3)\n", "D=(C*M)/N //Density\n", "printf('Density of Si=')\n", "printf('D=%.2f g/cm^3',D)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 5.3: calculate_surface_density_of_atoms.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "// chapter 5 , Example5 3 , pg 151\n", "//(1 1 1) plane for a BCC crystal\n", "a=5*10^-10//lattice constant (in m)\n", "//height of equilaterl triangle (shaded area) =a*sqrt(3/2)\n", "//hence area of shaded triangular portion is a*sqrt(2)*a*sqrt(3/2)/2 = a^2*sqrt(3)/2\n", "//every corner atom contributes 1/6to the area\n", "n111=(3/6)/(a^2*sqrt(3)/2) //planar concentration\n", "printf('surface density of atoms in (1 1 1)plane of BCC structure (in atoms/m^2)')\n", "disp(n111)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 5.4: calculate_spacing_of_planes.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "// chapter 5 , Example5 2 , pg 150\n", "a=4.049 //lattice constant(in Angstrom)\n", "h=2\n", "k=2\n", "l=0 //since (h k l)=(2 2 0) miller indices\n", "d=a/sqrt(h^2+k^2+l^2) //spacing\n", "printf('spacing of (2 2 0) planes=')\n", "printf('d=%.3f Angstrom',d)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 5.5: determine_size_of_unit_cell.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "// chapter 5 , Example5 5 , pg 152\n", "d110=2.03//spacing of(1 1 0) planes (in Angstrom)\n", "h=1\n", "k=1\n", "l=0 //(h k l)=(1 1 0)\n", "a=d110*sqrt(h^2+k^2+l^2)//size of unit cell\n", "printf('size of unit cell=')\n", "printf('a=%.2f angstrom',a)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 5.6: determine_spacing_between_planes.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "// chapter 5 , Example5 6 , pg 152\n", "a=5.64//lattice constant (in Angstrom)\n", "h1=1\n", "k1=0\n", "l1=0 //(h1 k1 l1)=(1 0 0)\n", "h2=1\n", "k2=1\n", "l2=0 //(h2 k2 l2)=(1 1 0)\n", "h3=1\n", "k3=1\n", "l3=1//(h3 k3 l3)=(1 1 1)\n", "d100=a/sqrt(h1^2+k1^2+l1^2) //spacing of (1 0 0)planes\n", "d110=a/sqrt(h2^2+k2^2+l2^2) //spacing of (1 1 0)planes\n", "d111=a/sqrt(h3^2+k3^2+l3^2) //spacing of (1 1 1)planes\n", "printf('spacing of (1 0 0) planes=')\n", "printf('d100=%.2f Angstrom\n',d100)\n", "printf('spacing of (1 1 0) planes=')\n", "printf('d110=%.2f Angstrom\n',d110)\n", "printf('spacing of (1 1 1) planes=')\n", "printf('d111=%.2f Angstrom',d111)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 5.7: find_volume_of_unit_cell.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "// chapter 5 , Example5 7 , pg 153\n", "r=1.605 *10^-10 //radius of atom (in m)\n", "a=2*r//lattice constant (for HCP structure) (in m)\n", "c=a*sqrt(8/3) //(in m)\n", "V=(3*sqrt(3)*a^2*c)/2 //volume of unit cell\n", "printf('volume of unit cell(in m^3)\n')\n", "disp(V)" ] } ], "metadata": { "kernelspec": { "display_name": "Scilab", "language": "scilab", "name": "scilab" }, "language_info": { "file_extension": ".sce", "help_links": [ { "text": "MetaKernel Magics", "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md" } ], "mimetype": "text/x-octave", "name": "scilab", "version": "0.7.1" } }, "nbformat": 4, "nbformat_minor": 0 }