Garnet magnetic moment

In yttrium iron garnet Y3Fe5012 ( YIG ) a ferrimagnetic coupling (superexchange) is active between the octahedral and the tetrahedral sites. Since the tetrahedral sites are in excess, the magnetic moments do not compensate each other. The magnetic properties can be varied by substitution of yttrium by lanthanoids. 

Bonnet, M., Delapalme, A., Tcheou, F., Fuess, H. Polarized neutron determination of magnetic moments and magnetic form factors of Fe + in yttrium iron garnet. Proc. Intern. Cong. Magnetism, Moscow 1973, IV, 251 (1974). 

M. Bonnet, A. Delapalme, F. Tcheou, and H. Fuess, Polarized Neutron Determination of Magnetic Moments and Magnetic Form Factors of in Yttrium Iron Garnet, Proceedings of the International Conference on Magnetism, Moscow (1973). 

In ionic crystals it seems reasonable that the background level should fall to zero at suitably chosen positions in the unit cell so that a moment integration may 3neld the local moment directly. Such a procedure was followed for integration around the octahedral and tetrahedral Fe3+ sites in yttrium iron garnet (72), where the position of the yttrium ion was chosen as the backgound level. This technique is particularly useful in such cases where there is more than one type of magnetic ion per unit cell. 

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