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Journal of Nanomaterials
Volume 2014, Article ID 703072, 9 pages
http://dx.doi.org/10.1155/2014/703072
Research Article

Effect of Mn-Site for Al Substitution on Structural, Electrical and Magnetic Properties in Thin Films by Sol-Gel Method

1Department of Electrical, Electronic and Systems Engineering, Faculty Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
2Physics Department, Faculty of Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia

Received 10 October 2013; Revised 14 January 2014; Accepted 28 January 2014; Published 26 March 2014

Academic Editor: Wanqin Jin

Copyright © 2014 H. Abdullah et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Nanocrystalline ( , 0.05, 0.10, 0.15, 0.20, and 0.25) thin films have been prepared on quartz substrates by sol-gel method. The structural and morphology studies were investigated via X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). XRD graph patterns show rhombohedral distorted perovskite structures. FESEM images show that the average grain size decreased as the concentration of increased. Electrical property was investigated using four-point probe technique. Resistivity results show that metal-insulator transition (MIT) temperatures ( ) decreased when the concentration of increased. shifted to lower temperature when the concentration of increased. The data was analyzed based on theoretical models, where the ferromagnetic resistivity is followed with the equation , where is due to the significance of grain boundary effects and a second-term ~ appears that might be applied to the electrons scattering. In the high temperature regime , the resistivity data can be well described by small polaron hopping (SPH) and variable range hopping (VRH) mechanisms. Magnetic property was investigated using a vibration sample magnetometer. All samples that were obtained showed hysteresis curve with the highest value of magnetization for sample .