The formula for yttrium iron garnet (Y3Fe5O12) may be written

The formula for yttrium iron garnet (Y3Fe5O12) may be written in the form

where the superscripts a, c, and d represent different sites on which the Y3+ and Fe3+ ions are located. The spin magnetic moments for the Y3+ and Fe3+ ions positioned in the a and c sites are oriented parallel to one another and antiparallel to the Fe3+ ions in d sites. Compute the number of Bohr magnetons associated with each Y3+ ion, given the following information: (1) each unit cell consists of eight formula (Y3Fe5O12) units; (2) the unit cell is cubic with an edge length of 1.2376 nm; (3) the saturation magnetization for this material is 1.0 A? 104 A/m; and (4) assume that there are 5 Bohr magnetons associated with each Fe3+ ion.