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

被引：89

作者：

Kuberkar, D. G. ^{[1
]}

Doshi, R. R. ^{[1
]}

Solanki, P. S. ^{[1
]}

Khachar, Uma ^{[1
]}

Vagadia, Megha ^{[1
]}

Ravalia, Ashish ^{[1
]}

Ganesan, V. ^{[2
]}

机构：

[1] Saurashtra Univ, Dept Phys, Rajkot 360005, Gujarat, India

[2] UGC DAE CSR, Indore 452017, Madhya Pradesh, India

来源：

APPLIED SURFACE SCIENCE | 2012年 / 258卷 / 22期

关键词：

Sol-Gel; Manganites; Grain morphology; Size disorder; GIANT MAGNETORESISTANCE; DEPENDENT TRANSPORT; BEHAVIOR;

D O I：

10.1016/j.apsusc.2012.05.149

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Nanostructured polycrystalline La0.7Ca0.3MnO3 (LCMO) and Nd0.7Sr0.3MnO3 (NSMO) manganites have been successfully synthesized at various temperatures ranging between 700 and 1100 degrees 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. (C) 2012 Elsevier B.V. All rights reserved.

引用

页码：9041 / 9046

页数：6

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