Details

Autor(en) / Beteiligte

• Kuberkar, D.G.
• Doshi, R.R.
• Solanki, P.S.
• Khachar, Uma
• Vagadia, Megha
• Ravalia, Ashish
• Ganesan, V.

Titel

Grain morphology and size disorder effect on the transport and magnetotransport in Sol–Gel grown nanostructured manganites

Ist Teil von

• Applied surface science, 2012-09, Vol.258 (22), p.9041-9046

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2012

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] ► Single phasic nanostructured manganites can be synthesized at low temperatures. ► Sol–Gel technique is low cost, simple and easy to handle. ► Grain morphology modifies the transport and magnetotransport properties. ► Surface contribution to the modifications in the transport and MR behavior. ► Interplay between low temperature extrinsic and room temperature intrinsic MR. Nanostructured polycrystalline La0.7Ca0.3MnO3 (LCMO) and Nd0.7Sr0.3MnO3 (NSMO) manganites have been successfully synthesized at various temperatures ranging between 700 and 1100°C using Sol–Gel method. Crystalline nature and morphology of the samples have been studied using XRD (Rietveld analysis) and TEM measurements. SEM studies reveal nanostructured grain morphology of LCMO and NSMO samples. It is observed that, with increase in sintering temperature, crystallinity and grain morphology get improved resulting in better transport. A strong dependence of transport on size variance has been observed in the systems studied. The modified transport and better magnetotransport properties of the manganites have been observed due to the large surface to volume ratio (surface contribution) in the nanostructured manganites. The observation of large low temperature MR in both the manganite systems and the interplay between the intrinsic and extrinsic MR components has been explained in the light of spin polarized tunneling effect, grain morphology, grain boundary nature and size disorder effect.