Orbital disorder

These hole-rich droplets represent a ferromagnetic second phase having a 7c < 7n the volume fraction of this minority phase grows with increasing x, and in the range 0.1 < x < 0.13 the droplets are condensed into large clusters having 7c > 7n. The crossover from 7c < 7n to 7c > 7n occurs at about x = 0.10 near a point where the 2D orbital order-disorder transition (or onset of orbitally disordered clusters) at T (same T as in fig. 14) crosses Tn. 

Figure 2. Crystal structure phase diagram of the Lao ssMnOx (2.82

Figure 3. Magnetic phase diagram for Lai-xSrxCMn xflNbxalCh series (A- antiferromagnet, F-ferromagnet, P- paramagnet, SG- spin glass O1 and O- orbitally ordered and orbitally disordered phases, respectively).

Paired JT distorted stripes or bistripes are believed to be present in Lao,3.iCao.67MnO,i. A supercell based on such ordering has been proposed, but a detailed structural investigation has shown that the diffraction data can be explained satisfactorily without bistripes. Apparently, owing to orbital disordering, a mixture of paired and unpaired stripes seems to occur in Lao.iiCao.sMnO. . Because such charge stripes generally are observed by electron microscopy, it is not clear whether these stmctures truly represent the bulk composition. 

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