Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1813824 | Physica B: Condensed Matter | 2017 | 5 Pages |
Abstract
Low-temperature magnetoresistance (MR) measurement has been carried out on nanocrystalline La0.8Sr0.2MnO3+δ manganites prepared by combustion synthesis. This preparation method yields voluminous powders with large surface area (â¼40 m2/g) having crystalline nanosize (â¼50 nm) products. Formation and homogeneity of the solid solutions have been confirmed by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Rietveld refinement of X-ray data indicates that as-formed compound exhibits cubic phase with space group Pm3 m. However, calcined sample transforms into rhombohedral phase with space group R-3c. The stabilization of the cubic phase in as-formed manganite is due to the substitution of Sr2+ on La3+ sites, resulting in higher Mn4+ content. The low-temperature resistivity measurements down to 70 K exhibit a broad metal-insulator transition (TMâI) at around 257 K. MR measurements on sintered pellets show â¼5% MR at 1 T, whereas for 4 and 7 T, the %MR values are found as 22% and 28%, respectively, at TMâI.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
B.M. Nagabhushana, R.P. Sreekanth Chakradhar, K.P. Ramesh, V. Prasad, C. Shivakumara, G.T. Chandrappa,