e-ISSN 2231-8542
ISSN 1511-3701

Home / Regular Issue / JTAS Vol. 17 (2) Jul. 2009 / JST-0068-2008


Low Sm Doping Effects on the Low-Field Magnetoresistive Properties in (La1-xSmx) 0.67Sr0.33MnO3 Perovskite

Lim Kean Pah, Abdul Halim Shaari, Chen Soo Kien, Ng Siau Wei, Zalita Zainuddin and Ye Chau Yuen

Pertanika Journal of Tropical Agricultural Science, Volume 17, Issue 2, July 2009

Keywords: Low-field magnetoresistance, polycrystalline manganites

Published on:

A series of polycrystalline samples (La1-xSmx) 0.67Sr0.33MnO3 (X=0.00, 0.05 and 0.10) were prepared using the conventional solid-state reaction method. The XRD analysis indicated that all the samples were fully crystalline and in a single phase with a rhombohedral structure after a sintering at 1200°C for 24 hours in air. Meanwhile, the Atomic Force Microscopy measurements showed that a small amount of Sm doping in La sites affected the grain growth and this might affect the grain boundary layer, thus resulting in the reduction of the Curie temperature, TC. Extrinsic magnetoresistance (MR) was observed for all the samples with a large negative MR at low field (0-0.1 or 0.2T) region, followed by a slower varying MR at high field (0.1 or 0.2-1T). The highest low-field MR value of -4.6% (at 0.1T) and -6.1% (at 0.2T) were observed for sample X=0.10 and X=0.05, respectively. Hence, these indicated that the extrinsic MR was grain size dependent and was therefore enhanced with a small amount of Sm substitution in La sites.

ISSN 1511-3701

e-ISSN 2231-8542

Article ID


Download Full Article PDF
Recent Articles