Answer to Question #249937 in Physics for SRI

Question

Calculate the number of Bohr magnetons per atom of iron, given that the saturation magnetization Ms=1.70à ƒ —106 A/m, that
iron has a BCC crystal structure, and that that the edge length of the cubic unit cell is 0.287 nm.

A) 3.60
B) 2.16
C) 3.48
D) 2.84

Answer 1

Calculate how many atoms there are in a cubic meter for BCC crystal:

$$N=2/a^3.$$

The number of Bohr magnetons can be found as

$$n_B=M_S/(\mu_BN)=M_Sa^3/(2\mu_B)=2.16.$$