Materials Chemistry and Physics 148 (2014) 988e999
Contents lists available at ScienceDirect
Materials Chemistry and Physics journal homepage: www.elsevier.com/locate/matchemphys
Cation distribution controlled dielectric, electrical and magnetic behavior of In3þ substituted cobalt ferrites synthesized via solid-state reaction technique Rabia Pandit a, K.K. Sharma a, *, Pawanpreet Kaur a, Ravi Kumar b, 1 a b
Department of Physics, National Institute of Technology, Hamirpur, H.P 177 005, India Centre for Material Science and Engineering, National Institute of Technology, Hamirpur, H.P 177 005, India
h i g h l i g h t s Rietveld refinement of CoInxFe2xO4 samples shows single phase cubic spinel structure. Cation distribution matches well with experimental integrated intensity ratios. Strength of magnetic interactions is found to increase with increasing In3þ substitution. The present systems are highly correlated. These material are promising candidate for power transformers at high frequencies.
a r t i c l e i n f o
a b s t r a c t
Article history: Received 21 March 2014 Received in revised form 13 August 2014 Accepted 13 September 2014 Available online 30 September 2014
We report the structural, cation distribution, dielectric, electrical and magnetic properties of CoFe2xInxO4 (0.0 x 0.6) ferrites. Rietveld fitted X-ray diffraction (XRD) patterns confirm the formation of single phase cubic spinel structure with Fd3m space group for all the samples. The comprehensive analysis of XRD based cation distribution has been performed to see the effect of In3þ ions substitution on various structural parameters such as site ionic radii, edge and bond lengths, interionic distances etc. The dielectric constant and tangent loss have been studied as a function of temperature and frequency. The dielectric data presented in electric modulus form reveals the presence of non-Debye relaxation behavior in considered ferrites. Both the AC and DC conductivities as a function of temperature are found to decrease with increasing In3þ content. The power law behavior of AC-conductivity indicates a strong correlation among electrons in these systems. The isothermal magnetization versus applied field curves with high field slope and significant coercivity suggest that studied materials are highly anisotropic with canted spin structures and exhibit ferrimagnetic behavior at 300 K. Magnetization gets enhanced up to 40% of In3þ substitution. The observed low dielectric losses and high resistivity can find their application in power transformers at high frequencies. © 2014 Elsevier B.V. All rights reserved.
Keywords: Rietveld analysis Magnetic materials Dielectric properties
1. Introduction The spinel ferrites have extensive applications in electronics and telecommunication industries owing to their intriguing electrical and magnetic properties [1e4]. The physical properties of ferrites can be further upgraded for various industrial applications upon
* Corresponding author. E-mail addresses:
[email protected] (R. Pandit),
[email protected],
[email protected] (K.K. Sharma). 1 Present address: Beant College of Engineering and Technology, Gurdaspur, Pb. 143 521, India. http://dx.doi.org/10.1016/j.matchemphys.2014.09.009 0254-0584/© 2014 Elsevier B.V. All rights reserved.
different trivalent metal ion's substitution, which play a crucial role in tuning such properties. Recently there has been a growing interest in the electrical and magnetic studies of In3þ substituted mixed as well as simple ferrites [5e8]. Rao et al. [5] noticed that the substitution of In3þ ions in NieZneTi ferrites improves their resistivity as well as magnetization. Hashim et al. [6] observed that upon In3þ substitution in Ni0.5Cu0.25Zn0.25Fe2xInxO4 ferrites, dielectric constant and saturation magnetization gets lowered. In another study on Zn2xSn1xInxO4d, (x ¼ 0.0, 0.45) spinel ferrite, Palmer et al. [7] reported an enhanced conductivity of Zn2SnO4 and the solubility limit of In3þ ions in Zn2SnO4 ~ 30%. An improvement in the electrical properties with increasing In3þ ion concentration
