Typical Cases Leading to Ferromagnetic Interaction

Interaction between two Mn and Mn sites (in octahedral environments) linked by a Mn-O-Mn bridge in the (a) FM and (b) AFM arrangements of their spins. Here it is assumed that Mn +Oe and Mn +Oe octahedra have the same structure. 

For the spin exchange between Mn2 (d ) and Mn3 (d ) ions in CaMn70 2 discussed earlier, we note that the O 2p tail of the x — magnetic orbital of the 

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