The influence of intrinsic site distortions on orbital and magnetic ordering in transitionmetal oxid

1
The structural bias effect on magnetic properties
in the perovskite oxides John B. Goodenough,
University of Texas at Austin, DMR 0555663

• The influence of intrinsic site
  distortions on orbital and magnetic ordering in
  transition-metal oxides is a key issue today in
  solid-state theory. We have monitored the
  evolution with R3-ion size (IR) of an intrinsic
  octahedral-site distortion that biases the
  orbital ordering in the RMO3 perovskites (R rare
  earth, M transition-metal). The figures show the
  orbital order and the evolution of the Mn-O bond
  lengths and magnetic order for the RMnO3
  perovskites. As IR decreases, the site bias
  reduces the s-bond ferromagnetic relative to the
  p-bond antiferromagnetic Mn-O-Mn interaction in
  the basal planes, and cross-over in the heavier
  R3 ions introduces and exchange wave.

2
Broader ImpactThe rule of local structural
distortions also provides a guide line for the
solid-state synthesis under pressure of this
category of materials.
The structural bias effect on magnetic properties
in the perovskite oxides John B. Goodenough,
University of Texas at Austin, DMR 0555663
9R
Prepared under ambient pressure
3GPa 1000oC
18 GPa 1000oC
5 GPa 1000oC
The multianvil high-pressure module which can
create 25 GPa pressure and about 2000? C, has
been established by retrofitting the existing
apparatus. Application of the technology in
solid-state chemistry will bring about a broad
range of new phases and new materials.
4H
6H
3C perovskite
The pathway of crystal structure of BaRuO3 under
high pressure