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from math import*
import numpy as np
from matplotlib import pyplot as plt
a=[]
Nep=10
for j in range(0,Nep):
a.append((119+650*j)/(1+j))
a=np.array(a)
Nfirst = 11
Ndown =21
Nup=21
c=0.03097619
k=498.13655
Ms=3.62970e+05
mu0 = 4 * np.pi * 1e-7
alpha=1.4982*10**(-4)
DeltaH = 10
delta = [0]
Man = np.zeros((54,10))
dMirrdH = []
Mirr = np.zeros((10,54))
M = [0]
B=np.zeros((54,10))
H = [0]
for j in range(Nfirst):
H.append(H[j] + DeltaH)
for j in range(Ndown):
H.append(H[-1] - DeltaH)
for j in range(Nup):
H.append(H[-1] + DeltaH)
H=np.array(H)
delta = [0]
for j in range(len(H) - 1):
if H[j + 1] > H[j]:
delta.append(1)
else:
delta.append(-1)
for j in range (Nfirst + Ndown + Nup) :
for i in range (0,Nep):
Man[j,i]= (Ms * (1 / np.tanh((H[j + 1] + alpha * H[j]) / a[i]) - a[i] / (H[j + 1] + alpha * M[j])))
dMirrdH[j]=((Man[j+1,i] - M[j]) / (k * delta[j+1] - alpha * (Man[j + 1] - M[j])))
Mirr[j]=(Mirr[j] + dMirrdH[j + 1] * (H[j+1] - H[j]))
M[j+1]=(c * Man[j + 1,i] + (1 - c) * Mirr[j + 1])
B[j+1,i]=(mu0 * (H[j+1]) + mu0 * M[j+1]) |
