Abstract
X-ray diffraction, resistivity, AC susceptibility and magnetization studies on La 0.67Ca 0.33Mn 1− x Ru x O 3 (0⩽ x<0.085) were carried out. A significant increase in the lattice parameters indicated the presence of mixed valence state of Ru: Ru 3+ and Ru 4+. The resistivity of the doped compounds exhibited two features: a broad hump and a relatively sharp peak. While a para- to ferromagnetic transition could be observed for the latter peak, no magnetic signal either in AC susceptibility or in magnetization measurements could be observed for the broad hump. The magnetic moment of Mn per unit cell decreases non-linearly from 3.55 to 3 μ B for the Ru compositions studied. Based on the results of the present studies and existing literature on Mn-site substituted systems, we argue that a magnetic phase separation occurs in the Ru-doped system. While the sharp peak in the resistivity corresponds to Ru 4+-enriched regions with ferromagnetic coupling of Ru with the neighboring Mn ions, the broad peak corresponds to Ru 3+-rich regions, with antiferromagnetic coupling of Ru with the neighboring Mn ions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
