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{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 16 : Magnetic Materials"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 16.1, Page No 396"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"a = 2.87 # lattice parameter in angstrom\n",
"n = 2 # number of atoms per unit cell\n",
"m = 1750 # Saturation magnetization in kAm^-1\n",
"mu = 9.273e-24 # bohr magneton \n",
"\n",
"#Calculations\n",
"m_atom = m*1e3*(a*1e-10)**3/n\n",
"mu_b = m_atom/mu\n",
"\n",
"#Results\n",
"print(\" Net magnetic moment per iron atom in crystal is %.3e Am^2\" %m_atom)\n",
"print(\" In unit of mu_b, Net magnetic moment per iron atom in crystal is %.1f \" %mu_b)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" Net magnetic moment per iron atom in crystal is 2.068e-23 Am^2\n",
" In unit of mu_b, Net magnetic moment per iron atom in crystal is 2.2 \n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 16.2, Page No 398"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"t1 = 0 \t\t\t# temperature in kelvin\n",
"t2 = 300.0 \t\t# temperature in kelvin\n",
"m_net_Gd = 7.0 \t# net magnetic moment of gadolinium\n",
"m_net_Co = 1.7 \t# net magnetic moment of cobalt\n",
"t_c_Gd = 289.0 # curie temperature for Gd\n",
"\n",
"#Calculations\n",
"print(\" Part A:\")\n",
"if m_net_Gd> m_net_Co :\n",
"\tprint(\" At %d K, Net magnetic moment of gadolinium i.e. %d is greater than net magnetic moment of cobalt i.e. %.1f \" %(t1,m_net_Gd,m_net_Co))\n",
"\tprint(\" So, Gd will have higher saturation magnetization\")\n",
"\n",
"print(\" Part B:\")\n",
"if t_c_Gd<t2 :\n",
" print(\" At temperature %d K, Gd is above its curie temperature of %dK\" %(t2,t_c_Gd))\n",
" print(\" Gd will be paramagnetic at %d K and will have negligible magnetization as compared to Co, which has higher curie temperature\" %t2)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" Part A:\n",
" At 0 K, Net magnetic moment of gadolinium i.e. 7 is greater than net magnetic moment of cobalt i.e. 1.7 \n",
" So, Gd will have higher saturation magnetization\n",
" Part B:\n",
" At temperature 300 K, Gd is above its curie temperature of 289K\n",
" Gd will be paramagnetic at 300 K and will have negligible magnetization as compared to Co, which has higher curie temperature\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 16.4, Page No 402"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"v = 0.01 # volume in m^3\n",
"x = 1e-4 # axis intercept\n",
"y = 1e2 # axis intercept\n",
"a = 60000.0 # Hysteresis loop area\n",
"f = 50.0 # frequency in Hz\n",
"\n",
"#Calculations\n",
"e = x*y*a # Energy loss in one loop\n",
"E = e*v # energy loss in core in one cycle\n",
"P = E*f # Power loss\n",
"\n",
"#Results\n",
"print(\" Power loss due to hysteresis is %d W\" %P)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" Power loss due to hysteresis is 300 W\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 16.5 Page No 405"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#initialisation of variables\n",
"Total1 = 2300.0 \t# total iron loss in W at 440 V and 50 Hz\n",
"Total2 = 750.0 \t# total iron loss in W at 220 V and 25 Hz\n",
"\n",
"#Calculations\n",
"W_e = 1.0/2*(Total1-2*Total2)\n",
"\n",
"#Results\n",
"print(\" Eddy current loss at normal voltage and frequency is %d W\" %(4*W_e))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" Eddy current loss at normal voltage and frequency is 1600 W\n"
]
}
],
"prompt_number": 4
}
],
"metadata": {}
}
]
}
|
