Question

Calculate the Hall coefficient of sodium based on free electron model. Sodium has bcc structure and the side of the cube is 4.28 Å.

2.45 ×10−9 m3 C−1

3.28 ×10−9 m3 C−1

4.50 ×10−9 m3 C−1

1.65 ×10−9 m3 C−1

Answer 1

Find the carrier concentration:

$$n=\frac{N_AZ\rho_m}{m_a}=\frac{(6.022·10^{23})·1·968}{23·10^{-3}}=2.53·10^{28}\text{ m}^{-3}.$$

Hall coefficient:

$$R_H=\frac1{ne}=2.46·10^{-10}\text{ m}^3/\text C.$$