28 lines
702 B
Python
Executable File
28 lines
702 B
Python
Executable File
#!/usr/bin/env python3
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#Program fitting the exchange interaction
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#Model curve: Bethe-Slater function
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import numpy as np, pylab, tkinter
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import matplotlib.pyplot as plt
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import mpmath as mp
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# from scipy.optimize import curve_fit
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# from decimal import *
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mub=5.78901e-5 # Bohr magneton (eV/T)
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kb=8.617333262145e-5 # Boltzman constant (eV/K)
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g=2.0 # Lande factor (adim)
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Hz=10.0 # mag. field (T)
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#Definition of the Langevin function
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def func(t):
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return mp.coth(g*mub*Hz/(kb*t))-1.0/(g*mub*Hz/(kb*t))
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npoints=200
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ti=0.01
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tf=20.0
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for i in range (0,npoints):
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temp=ti+i*(tf-ti)/npoints
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print('%lf %lf %lf' % (temp,func(temp),-g*mub*Hz*func(temp)))
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