Departmental Papers (MSE)

Document Type

Journal Article

Date of this Version

September 2004


The perovskite solid solution between ferromagnetic SrRuO3 and antiferromagnetic LaCoO3 is studied and its structural, electronic,and magnetic properties are compared with (Sr1-xLax)(Ru1-xFex)O3. The lower 3d energy levels of Co3+ cause a local charge transfer from 4d Ru4+, a reaction that has the novel feature of being sensitive to the local atomic structure such as cation order. Despite such a complication, Co, like Fe, spin-polarizes the itinerant electrons in SrRuO3 to form a large local magnetic moment that is switchable at high fields. In the spin glass regime when Anderson localization dominates, a large negative magnetoresistance emerges as a result of spin polarization of mobile electronic carriers that occupy states beyond the mobility edge. A phenomenological model predicting an inverse relation between magnetoresistance and saturation magnetization is proposed to explain the composition dependence of magnetoresistance for both (Sr1-xLax)(Ru1-xCOx)O3 and (Sr1-xLax)(Ru1-xFex)O3 systems.


Copyright American Physical Society. Reprinted from Physical Review B, Volume 70, Issue 10, Article 104410, September 2004, 11 pages.
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Date Posted: 20 December 2005

This document has been peer reviewed.