Polycrystalline (In1-xNix)2O3 thin films (x=0.00, 0.03, 0.05 and 0.07) were deposited on glass substrates by electron beam evaporation technique. The effect of Ni concentration on composition, structural and magnetic properties of (In1-xNix)2O3 thin films was studied. Increment in the Ni concentration does increase the oxygen vacancies and ferromagnetic strength in (In1-xNix)2O3 thin films. X-ray photoelectron spectroscopy (XPS) studies indicate the dopant Ni exists in Ni (II) state in In2O3 host. Ferromagnetism was attributed to intrinsic nature of the sample rather than any secondary magnetic phases exist in the films. The observed ferromagnetism in (In1-xNix)2O3 was attributed to ferromagnetic exchange interaction between Ni2+ ions via single free electron trapped in oxygen vacancy. Increase in oxygen vacancies with Ni concentration lead to increase in such an oxygen vacancy mediated ferromagnetic pairs resulting in increase in ferromagnetic strength with Ni concentration. © 2015 Elsevier B.V. All rights reserved.

Shaik Kaleemulla

Department of Physics

School of Advanced Sciences

Vellore Campus

Krishnamoorthi C

Sai Krishna N

Amarendra G

Madhusudhana Rao N

Rigana Begam M

Omkaram I

Sreekantha Reddy D.

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Physica B: Condensed Matter

Indium-tin-oxide (ITO) (In0.95Sn0.05)2O3 and Cr doped indium-tin-oxide (In0.90Sn0.05Cr0.05)2O3 nanoparticles were prepared using simple low cost solid state reaction method and characterized by different techniques to study their structural, optical and magnetic properties. Microstructures, surface morphology, crystallite size of the nanoparticles were studied using X-ray diffractometer (XRD), field emission scanning electron microscope (FE-SEM). From these methods it was found that the particles were about 45 nm. Chemical composition and valence states of the nanoparticles were studied using energy dispersive analysis of X-rays (EDAX) and X-ray photoelectron spectroscopy (XPS). From these techniques it was observed that the elements of indium, tin, chromium and oxygen were present in the system in appropriate ratios and they were in +3, +4, +3 and −2 oxidation states. Raman studies confirmed that the nanoparticle were free from unintentional impurities. Two broad emission peaks were observed at 330 nm and 460 nm when excited wavelength of 300 nm. Magnetic studies were carried out at 300 K and 100 K using vibrating sample magnetometer (VSM) and found that the ITO nanoparticles were ferromagnetic at 100 K and 300 K. Where-as the room temperature ferromagnetism completely disappeared in Cr doped ITO nanoparticles at 100 K and 300 K. © 2016 Elsevier B.V.

Microstructure, ferromagnetic and photoluminescence properties of ITO and Cr doped ITO nanoparticles using solid state reaction

The optical and electrical properties are the two important dimensions of Indium oxide and its derivatives (indium tin oxide) and were well studied to understand the origin of wide electronic band gap and high electrical conductivity at room temperature. In2O3 and its derivatives find many applications in electronic and optoelectronic domains based on the above properties. The recent discovery of ferromagnetism in In2O3 at room temperature become a third dimension and lead to intensive research on enhancement of ferromagnetic strength by various means such as dopants and synthesis protocols and extrinsic parameters. The research lead to enormous experimental data and theoretical models proliferation over the past one decade with diverse insights into the origin of ferromagnetism in In2O3 based dilute magnetic semiconductors. The experimental data and theoretical models of ferromagnetism in In2O3 has been thoroughly surveyed in the literature and compiled all the data and presented for easy of understanding in this review. We have identified best chemical composition, geometry and synthesis protocols for strongest ferromagnetic strength and suitable theoretical model of magnetism has been presented in this review. © 2016 Elsevier B.V. All rights reserved.

Journal of Magnetism and Magnetic Materials

Indium oxide: A transparent, conducting ferromagnetic semiconductor for spintronic applications

Sn1-xFexO2 (x = 0.07) thin films were prepared on to glass substrates using flash evaporation technique and annealed in air at different temperatures. The X-ray diffraction study showsed that all the thin films annealed at different temperatures were in tetragonal rutile structure of SnO2. The Elemental analysis confirms the presence of Fe and Sn and O in the films. The magnetic measurements were carried out using vibrating sample magnetometer and found that the strength of magnetization decreased with increase of annealing temperature. © 2016 Author(s).

AIP Conference Proceedings

Effect of air annealing on structure and magnetic properties of Sn1-xFexO2 thin films

Magnetic, magnetoresistivity and superconductivity studies were carried out on (In1-xFex)2O3 (x = 0.00, 0.03, 0.05 and 0.07) thin films (2D structures) grown on glass substrate by electron beam evaporation technique at 350 C. The films have an average size of 120 nm particles. All the samples shown soft ferromagnetic hysteresis loops at room temperature and saturation magnetization increased with iron dopant concentration. Observed magnetization could be best interpreted by F-center mediated magnetic exchange interaction in the samples. Temperature dependent resistivity of the sample (x = 0.00 and 0.07) showed metallic behavior down to very low temperatures and superconductivity at 2 K for undoped In2O3 whereas the In1.86Fe0.14O3 sample shows superconductivity below 2 K in the absence of magnetic fields. The reduction in transition temperature was attributed to increase electrical disorder with iron doping. Both samples showed positive magnetoresistivity (MR) in superconducting state due to increase of resistivity resulting from breaking of superconducting Cooper pairs upon application of magnetic field. In addition, both the samples show feeble negative MR in normal electrical state. The observed MR in normal state is not due to spin polarized tunneling instead it is due to suppression of scattering of charge carrier by single occupied localized states. © 2015 Elsevier B.V. All rights reserved.

Journal of Alloys and Compounds

Magnetic and superconductivity studies on (In1−Fe )2O3 thin films

Nickel-doped indium oxide diluted magnetic semiconducting powders ((In 1-xNix)2O3, x=0.00, 0.03, 0.05, 0.07 and 0.09) were synthesized by a simple solid state reaction followed by vacuum annealing. Structural, optical and magnetic properties of (In 1-xNix)2O3 powders were studied as a function of doped Ni concentration. X-ray diffraction confirmed polycrystalline cubic structures. Decrease in optical band gap from 3.07 eV to 2.99 eV was observed when dopant concentration of Ni was increased from x=0.03 to x=0.07. Vibrating sample magnetometer measurements confirmed that all (In 1-xNix)2O3 powders were ferromagnetic at room temperature. © 2013 Elsevier Ltd. All rights reserved.

Journal	Data powered by TypesetPhysica B: Condensed Matter
Publisher	Data powered by TypesetElsevier BV
ISSN	0921-4526
Open Access	0