Co And Fe Doped SnO2 nanorods By Ce Co-doping And Their Electrical And Magnetic Properties

¹Department of Physics, Eternal University, Baru Sahib, Sirmour (H.P.) 173101, India

²National Physical Laboratory, New Delhi 110012, India

³Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India

Adv. Mater. Lett., 2012, 'ICNANO 2011', 3 (6), pp 511-514

DOI: 10.5185/amlett.2012.icnano.142

Publication Date (Web): Sep 23, 2012

Copyright © IAAM-VBRI Press

E-mail: jasneet.physics@gmail.com

Abstract

In the present work, the self-assembly of Co²⁺ and Fe³⁺ doped SnO₂ nanoparticles (Co and Fe = 5 mol% each) into nanorods by co-doping of Ce³⁺ (4 mol%) ions is studied. The nanorods are prepared by a chemical route using polyvinyl alcohol as surfactant with the composition Sn_0.91Co_0.05Ce_0.04O₂ (SCC54) and Sn_0.91Fe_0.05Ce_0.04O₂ (SFC54). The X-ray diffraction (XRD), transmission electron microscopy (TEM), magnetic and electrical measurements are used to characterize these nanorods. The XRD pattern show the tetragonal rutile and polycrystalline nature of SnO₂ nanorods which is also confirmed by TEM. The TEM images exhibit that the diameter of SCC54 nanorods lie in the range of 15-20 nm, length~100-200 nm whereas for SFC54 specimen, diameter ~5-15 nm and length ~50-100 nm. In our previous work, we fabricated Co and Fe (3 and 5 mol% each) doped SnO₂ nanoparticles which exhibited high ferromagnetism. It is observed that on Ce³⁺ co-doping, nanoparticles assembled themselves into rod like structures and the values of saturation magnetization and dielectric properties have further enhanced. Thus the nature and the concentration of dopants are found to play crucial role in tuning the morphology, magnetic and electrical properties of nanostructures. The values of saturated magnetization (Ms) are 1.14 and 0.14 emu/g and coercive field are 112 and 42 Oe, in SCC54 and SFC54 specimen, respectively, at room temperature. The variation in dielectric behavior is attributed due to the interface polarization. However, in lower frequency regime, the decreasing trend of dielectric permittivity with increasing frequency is explained by the Maxwell-Wagner theory and Koops’ model, whereas, in higher frequency region, the resonant behavior is observed due to nano size effect.

Keywords

Nanorods, sol-gel, TEM, magnetic properties, dielectric behavior.