# Chapter 10: Superconductivity¶

## Example 10.1, Page number 10.3¶

In [1]:
#Variable declaration
Tc = 3.7       #critical temperature(K)
Hc_o = 0.0306  #critical field(T)
T = 2          #temperature(K)

#Calculation
Hc_2 = Hc_o*(1-((T/Tc)**2))

#Result
print "Critical field at 2K is",round(Hc_2,5),"T"

Critical field at 2K is 0.02166 T


## Example 10.2, Page number 10.5¶

In [2]:
from math import pi

#Variable declaration
T = 4.2        #temperature(K)
Tc = 7.18      #critical temperature(K)
Ho = 6.5*10**4 #A/m
d = 1*10**-3   #diameter(m)

#Calculations
Hc = Ho*(1-((T/Tc)**2))
r = d/2
ic = 2*pi*r*Hc

#Result
print "Critical current =",round(ic,2),"A"

Critical current = 134.33 A


## Example 10.3, Page number 10.12¶

In [7]:
import math

#Variable declaration
T = 3.5         #temperature(K)
lamda_t = 750   #penetration depth at T(A)
Tc = 4.12       #K

#Calculation
lamda_o = lamda_t*math.sqrt((1-((T/Tc)**4)))

#Result
print "Penetration depth at 4.12K is",round(lamda_o,1),"A"

Penetration depth at 4.12K is 519.2 A


## Example 10.4, Page number 10.13¶

In [18]:
import math

#Variable declaration
T1 = 3          #temperature(K)
lamda_t1 = 396.  #penetration depth at T1(A)
T2 = 7.1        #temperature(K)
lamda_t2 = 1730. #penetration depth at T2(A)

#Calculations
x = lamda_t2**2/lamda_t1**2
Tc = math.sqrt(math.sqrt((-T1**4+(x*(T2**4)))/(x-1)))

#Result
print "Critical temperature =",round(Tc,3),"K"

Critical temperature = 7.193 K