Back to Search
Start Over
A-site disorder induces magnetoresistance in Y and Sr co-doped La2/3−x Y x Ca1/3−y Sr y MnO3
- Source :
-
Journal of Alloys & Compounds . Jul2005, Vol. 397 Issue 1/2, p250-254. 5p. - Publication Year :
- 2005
-
Abstract
- Abstract: Cations of Y and Sr co-substituting for La and Ca at A site in La2/3Ca1/3MnO3 compound, La2/3−x Y x Ca1/3−y Sr y MnO3, were synthesized successfully by solid-state reaction. X-ray diffraction shows there is only one phase with the dopants of Y and Sr within x ≤0.20 or y ≤0.19. The lattice parameters along a-, b-, and c-direction remain almost unchanged with x ≤0.20. The bond angle of Mnh name="sbnd" />Mn increases from 151.9° for x =0 to 172.7° for x =0.20 monotonically, which indicates that the Jahn–Teller effect in MnO6 octahedron decreases with increasing x. The temperature dependence of resistance with/without magnetic applied were measured and fitted theoretically. The metal-to-insulator transition temperature, T MI, decreases with increasing the Y content with x ≤0.10 while T MI increases slightly with further increasing x. The Y-content dependence of magnetoresistance shows a parabolic behavior. The maximum MR value corresponds to x =0.08–0.10. We attributed these variations in the structure and transportation to the cation disorder due to the cation doping. [Copyright &y& Elsevier]
- Subjects :
- *MAGNETIC fields
*CATIONS
*COLD (Temperature)
*TEMPERATURE
Subjects
Details
- Language :
- English
- ISSN :
- 09258388
- Volume :
- 397
- Issue :
- 1/2
- Database :
- Academic Search Index
- Journal :
- Journal of Alloys & Compounds
- Publication Type :
- Academic Journal
- Accession number :
- 17951649
- Full Text :
- https://doi.org/10.1016/j.jallcom.2004.11.068