Intrinsic structural distortion and superexchange interaction in the orthorhombic rare-earth perovskites R CrO3

Abstract

High-resolution neutron powder diffraction has been applied to determine the structural evolution in the orthorhombic perovskite R CrO3 family. The structural distortions observed have been found to be closely related to the dramatic variation in the magnetic ordering temperature T N. In addition to the reduction in the orbital overlap integral that can account for the change in TN in the R FeO3 family, the effect of t-e hybridization due to the structural distortions are responsible for the dramatic change in TN across the R CrO3 family. © 2010 The American Physical Society.