Question

The critical temperature of Nb is 9.15 K. At zero kelvin the critical field is
0.196 tesla. Calculate the critical field at 6K.

Answer 1

The critical field at 6k is 0.011 Telsa.

Explanation: The critical field at 6k , we have the formula for critical field

•            Hc(T) = Hc(0)[ 1 - (T/Tc)²]

Here given Critical field at zero Temperature Hc(0) = 0.0196,    Critical temperature Tc = 9.15k, and find critical field at T = 6K

Therefore

•                    Hc(T) = Hc(0)[ 1 - (T/Tc)²]
•                    Hc(T) = 0.0196[ 1 - (6/9.15)²]
•                    Hc(T) = 0.0196x0.57  
•                    Hc(T) = 0.011 Telsa