Chemical tuning of structure, magnetization, and conductivity in the self-doped double-perovskite (Sr2-xCax)FeMoO6 (0 ≤ x ≤ 2.0) System
Journal
Chemistry of Materials
Journal Volume
15
Journal Issue
2
Pages
425-432
Date Issued
2003
Author(s)
Abstract
The variations of crystal structure, magnetization, and conductivity resulting from the chemical pressure effects of substituting Sr2+ by the smaller Ca2+ in the double-perovskite (Sr2-xCax)FeMoO6 have been investigated. An increase in the Ca content leads to an increase in the Fe/Mo ordering in the materials, which raises the magnetic moments close to the theoretical value of 4 μB. An increase in conductivity with increasing Ca content is also found and is consistent with an increase in (Fe2+ + Mo6+)/(Fe3+ + Mo5+) band overlap rather than bandwidth changes. The changes observed by physical measurements are supported by the X-ray absorption near-edge structures of Fe and Mo and by band structure calculations.
Type
journal article