MICROSTRUCTURE AND MAGNETORESISTANCE OFCaCuxMn3-xMn4O12
| Autor: | Kaiming Deng, X. S. Wu, Wenyi Tan, H. Cao, G. J. Xu, H.P. Wu |
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| Rok vydání: | 2011 |
| Předmět: |
Materials science
Colossal magnetoresistance Magnetoresistance Rietveld refinement Analytical chemistry chemistry.chemical_element Statistical and Nonlinear Physics Crystal structure Manganese Condensed Matter Physics Microstructure Nuclear magnetic resonance chemistry X-ray crystallography Ambient pressure |
| Zdroj: | International Journal of Modern Physics B. 25:83-89 |
| ISSN: | 1793-6578 0217-9792 |
| Popis: | In this article, the precursors of CaCuxMn3-xMn4O12(x = 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4) were synthesized using wet-chemistry technique, and then samples were sintered in pure oxygen flow at 850°C and ambient pressure with KCl 10 wt% addition. The Rietveld refinements of powder X-ray diffraction patterns showed that all the samples were single phase with cubic symmetry, the space group [Formula: see text]. The lattice parameters a decreased with increasing Cu doping level x. The transport properties were characterized with DC four-probe technique. The results indicated that the crystal structure of samples were deformed and then influenced the transport properties of these manganese oxides. The MR ratios at 85 K and in the magnetic field of 5 Tesla increased with increasing x and reached the maximum at x = 1.0, then decreased with further increasing x. These results originated maybe from the intergrain tunneling of spin-polarized carriers and double-exchange effect. |
| Databáze: | OpenAIRE |
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