Double-exchange mechanism

The fact that LSMO is ferromagnetic in the charge-ordered, insulating state is remarkable, since it indicates that the ferromagnetic interaction at low temperatures cannot arise from the double exchange mechanism. We note here that other... 

A mechanism to account for the parallel spin alignment between the Fe in the octahedral site and the octa-hedrally coordinated Fe was proposed by Zener and is called the double exchange mechanism. The idea is that an electron from the Fe ion (3d ) is transferred to the oxygen in the face-centered position of the subcell shown in Figme 33.12. At the same time there is transfer of an... 

Zener, C (1951) Interaction between the d-shells in the transition metals, Phys. Rev. 81,440 and Interaction between the d-shells in the transition metals 2 Ferromagnetic compounds of manganese with perovskite structure, Phys. Rev. 82, 403. These two papers have been cited collectively almost 4000 times and describe the double exchange mechanism. Clarence Zener spent a short time (1940-1942) as an instructor at Washington State University when it was still known as Washington State College. 

At higher temperatures, the ordering forces involved in the double exchange mechanism are disrupted by thermal agitation. Eventually this overcomes the... 

Fig. 6.3 Double exchange mechanism proposed by Zener consisting in the simultaneous hopping of an electron from center 1 to the bridge and from the bridge to metal 2...

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