{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "#6(B): Superconductivity" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "##Example number 6.2, Page number 6.55" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "critical field is 33.64 *10**3 ampere/m\n" ] } ], "source": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "H0=64*10**3; #initial field(ampere/m)\n", "T=5; #temperature(K)\n", "Tc=7.26; #transition temperature(K)\n", "\n", "#Calculation\n", "H=H0*(1-(T/Tc)**2); #critical field(ampere/m)\n", "\n", "#Result\n", "print \"critical field is\",round(H/10**3,2),\"*10**3 ampere/m\"" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "##Example number 6.3, Page number 6.56" ] }, { "cell_type": "code", "execution_count": 4, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Frequency of generated microwaves= 483.0 *10**9 Hz\n" ] } ], "source": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "e=1.6*10**-19\n", "V=1*10\n", "h=6.625*10**-34\n", "\n", "#Calculations\n", "v=(2*e*V**-3)/h \n", "\n", "#Result\n", "print\"Frequency of generated microwaves=\",round(v/10**9),\"*10**9 Hz\"\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "##Example number 6.4, Page number 6.56" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Number of electrons per unit volume = 3.7 *10**28/m**3\n", "Effective mass of electron 'm*' = 17.3 *10*-31 kg\n", "Penetration depth = 3.81011659367 Angstroms\n", "#The answer given in the text book is wrong\n" ] } ], "source": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "d=7300 #density in (kg/m**3)\n", "N=6.02*10**26 #Avagadro Number\n", "A=118.7 #Atomic Weight\n", "E=1.9 #Effective mass\n", "e=1.6*10**-19\n", "\n", "#Calculations\n", "n=(d*N)/A\n", "m=E*9.1*10**-31\n", "x=4*math.pi*10**-7*n*e**2\n", "lamda_L=math.sqrt(m/x)\n", " \n", "#Result\n", "print \"Number of electrons per unit volume =\",round(n/10**28,1),\"*10**28/m**3\"\n", "print\"Effective mass of electron 'm*' =\",round(m*10**31,1),\"*10*-31 kg\"\n", "print\"Penetration depth =\",lamda_L*10**8,\"Angstroms\"\n", "print\"#The answer given in the text book is wrong\"" ] }, { "cell_type": "markdown", "metadata": { "collapsed": true }, "source": [ "##Example number 6.5, Page number 6.56" ] }, { "cell_type": "code", "execution_count": 18, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Tc = 7.0969 K\n", "lamda0= 39.0 nm\n" ] } ], "source": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "lamda_L1=39.6*10**-9\n", "lamda_L2=173*10**-9\n", "T1=7.1\n", "T2=3\n", "\n", "#Calculations\n", "x=(lamda_L1/lamda_L2)**2\n", "Tc4=(T1**4)-((T2**4)*x)/(1-x)\n", "Tc=(Tc4)**(1/4)\n", "print\"Tc =\",round(Tc,4),\"K\"\n", "print\"lamda0=\",round((math.sqrt(1-(T2/Tc)**4)*lamda_L1)*10**9),\"nm\"" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "##Example number 6.6, Page number 6.57" ] }, { "cell_type": "code", "execution_count": 24, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Hc = 4.2759 *10**4\n", "Critical current density,Jc = 1.71 *10**8 ampere/metre**2\n" ] } ], "source": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "H0=6.5*10**4 #(ampere/metre)\n", "T=4.2 #K\n", "Tc=7.18 #K\n", "r=0.5*10**-3\n", "\n", "#Calculations\n", "Hc=H0*(1-(T/Tc)**2)\n", "Ic=(2*math.pi*r)*Hc\n", "A=math.pi*r**2\n", "Jc=Ic/A #Critical current density\n", "\n", "#Result\n", "print\"Hc =\",round(Hc/10**4,4),\"*10**4\"\n", "print \"Critical current density,Jc =\",round(Jc/10**8,2),\"*10**8 ampere/metre**2\"\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "##Example number 6.7, Page number 6.57" ] }, { "cell_type": "code", "execution_count": 26, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "New critical temperature for mercury = 4.145 K\n" ] } ], "source": [ "#importing modules\n", "import math\n", "from __future__ import division\n", "\n", "#Variable declaration\n", "Tc1=4.185\n", "M1=199.5\n", "M2=203.4\n", "\n", "#Calculations\n", "Tc2=Tc1*(M1/M2)**(1/2)\n", "\n", "#Result\n", "print\"New critical temperature for mercury =\",round(Tc2,3),\"K\"" ] } ], "metadata": { "kernelspec": { "display_name": "Python 2", "language": "python", "name": "python2" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 2 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython2", "version": "2.7.9" } }, "nbformat": 4, "nbformat_minor": 0 }