Calculate the limiting value of the magnetic field for which Nb will act as a
superconductor at 4 K. Take Bac(0) as 1970 Oe and Tc for Nb to be 9.25 K.
Show that for a square lattice in two dimensions the kinetic energy of a free electron at a
corner of the first Brillouin zone is higher than that of an electron at the midpoint of a
side face of the zone by a factor of 2.
Aluminium has three valence electrons per atom, an atomic weight of 0.02698 kg mol−1,
a density of 2700kgm-3, and a conductivity of 3.54× 107 W−1m−1. Calculate the relaxation
time in Aluminium.
The Debye temperature for silver is 225 K. Calculate the highest possible frequency for
lattice vibrations in silver and its molar heat capacity at 10 K and 500 K.