Iron has a bcc structure with a lattice constant a: 2.86 a a) using the value of the saturation magnetization in table 9.6, show that the dipole moment of an fe atom is equal to 2.22 ub. the density of fe is 1.92 g/cm', and its atomic weight is 55.6. (you may assume, for the present purpose, that the 3d electrons are completely localized.) b) calculate the weiss exchange constant λ and the molecular field in iron c) evaluate the curie constant in iron d) estimate the exchange energy for a dipole interacting with its nearest neighbors. curic temperature and saturation magnetizations for ferromagnetic substancesf ( is the number of magnetons per unit at 0 k) substance t. k m, at 0°k , at 0 k 1.74 × 106 amp-m 1.45 0.5 2.01 2.92 fe co 1043 1403 631 289 105 515 410 480 130 2.22 1.72 0.54 7.10 10.1 gd cro2 mnofe203 feofe203 y fe o12(yig) 2.03 5.0 5.0 0.2