|
|||||
|
|
Magnetic pair making and breaking effect of Ru in La0.7Sr0.3Mn0.9Ru0.1O3 and La0.5Sr0.5Co0.9Ru0.1O3 |
|
| Authors: | Brajendra Singh , Ranjan K. Sahu , S. Sundar Manoharan , K. D rr ,K. -H. Mü ller |
| Affiliation: | a Indian Institute of Technology, Kanpur, UP-208 016, India b Inter University Consortium for DAE Facilities, Mumbai Centre, Bhabha Atomic Research Centre, R-5Shed, Mumbai 400 085, India c Institute of Solid State and Materials Research, P.O. Box 270016, D-01069, Dresden, Germany |
| Abstract: | The substitutional effect of Ru on the magnetic and transport properties of double exchange ferromagnets, La0.7Sr0.3MnO3 and La0.5Sr0.5CoO3 has been investigated. It is found that substitution of 10% Ru at the Mn site of La0.7Sr0.3MnO3 decreases the Curie temperature by 20 K than that of the parent compound. However, a large decrease in the Curie temperature, ΔTc80 K and the system undergoes a transition from metallic state to insulating state is observed when 10% Ru is doped in La0.5Sr0.5CoO3. The marginal effect of Ru in the Mn–O–Mn sublattice in comparison to the Co–O–Co sublattice could be due to the magnetic exchange interaction between Mn and Ru by virtue of the fact that Ru exhibits variable valence states, Ru+4/Ru+5. The eg and t2g parentage of Ru+5 is similar to Mn+4 and therefore, Ru+5 ion appears to participate in the double exchange mediated ferromagnetic (FM) interaction. On the other hand, Ruthenium (IV) ion disrupts an intermediate spin state of cobalt (Co+3: t2g5eg1), forcing a double exchange FM state to anti-FM state. |
| Keywords: | Author Keywords: Magnetically ordered materials Chemical synthesis Electron transport Order–disorder effect |
| 本文献已被 ScienceDirect 等数据库收录！ | |