Effect of Substrate Temperature on Structural and Optical Properties of Nanocrystalline CdTe Thin Films Deposited by Electron Beam Evaporation

Nanocrystalline Cadmium Telluride (CdTe) thin films were deposited onto glass substrates using electron beam evaporation technique. The effect of substrate temperature on the structural, morphological and optical properties of CdTe thin films has been investigated. All the CdTe films exhibited zinc blende structure with (111) preferential orientation. The crystallite size of the films increased from 35 nm to 116 nm with the increase of substrate temperature and the band gap of the films decreased from 2.87 eV to 2.05 eV with the increase of the crystallite size. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3195

Effect of Annealing on Structural and Optical Properties of Cu Doped In2O3 Thin Films

Cu-doped In2O3 thin films were prepared using flash evaporation method at different Cu-doping levels. The effect of annealing was studied on the structure, morphology and optical properties of the thin films. The films exhibited cubic structure and optical transmittance of the films increasing with annealing temperature. The highest optical transmittance of 78 % was observed with band gap of 4.09 eV. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3553

Structural, Optical and Magnetic Properties of (In0.90Sn0.05Cu0.05)(2)O-3 Nanoparticles

This study examined structural, optical and magnetic properties of ITO (In0.95Sn0.05)(2)O-3 and Cu doped ITO (In0.90Sn0.05Cu0.05)(2)O-3 nanoparticles synthesized by solid state reaction method. The synthesized nanoparticles were subjected to structural, optical and magnetic studies. The structural properties of the nanoparticles were carried out using XRD, Raman, FT-IR characterization techniques. Optical properties of the samples were studies using UV-Vis-NIR spectrophotometer. The magnetic measurements were carried out using vibrating sample magnetometer. The ITO (In0.95Sn0.05)(2)O-3 nanoparticles exhibited room temperature ferromagnetism with clear hysteresis loop. The strength of magnetization decreased in Cu doped ITO (In0.95Sn0.05)(2)O-3. The ITO nanoparticles were also exhibited ferromagnetism at 100 K with a magnetic moment of 0.02 emu/g

Structural, Optical, and Magnetic Properties of Co Doped CdTe Alloy Powders Prepared by Solid-State Reaction Method

Co doped CdTe powder samples were prepared by solid-state reaction method. In the present work effect of Co doping on structural, optical, and magnetic properties has been studied. X-ray diffraction studies confirm zinc blend structure for all the samples. The lattice parameter showed linear increase with the increase in Co content. The elemental constituents were characterized by EDAX. Optical studies showed the increase in band gap with increase in Co level. The samples were diluted magnetic semiconductors and exhibited clear hysteresis loop showing room temperature ferromagnetism as confirmed by vibrating sample magnetometer

Investigation of Spinel Structure ZnFe1.8La0.2O4 Nanoparticles Synthesized by PEG Assisted Wet Chemical Method

International audienceRare-earth substituted zinc ferrite nanoparticles with the chemical formula ZnFe1.8La0.2O4 have been successfully synthesized via a polyethylene glycol (PEG) assisted facile hydrothermal route. The influence of La substituted zinc ferrite nanoparticles was investigated using various techniques. The structure, crystallite size, functional group, optical properties, surface morphology and elemental analysis of synthesized sample were analyzed by Powder X-ray diffraction (PXRD), Fourier transform spectroscopy (FTIR), UV–visible spectroscopy, scanning electron microscopy (SEM) and energy-dispersive spectrometer (EDS). The PXRD pattern analysis indicated the formation of a simple cubic spinel structure. Also, using Debye-Scherrer equation, the average crystallite size of the particles was calculated to be about 15.06 nm. FT-IR studies confirmed the tetrahedral and octahedral sites in its cubic spinel structure. UV–visible spectrum of the sample showed absorbance peak in the wavelength range between 200-800 nm. The optical energy band gap was calculated to be 2.03 eV. Surface morphology analysis by Scanning Electron Microscope (SEM) shows the formation of ununiformed agglomerated nanoparticles. Elemental composition of synthesized sample was obtained from combined SEM–EDX measurements which confirmed the presence of Zn, Fe, La and O ions

Synthesis and Characterizations of (In0.90Sn0.05Ni0.05)(2)O-3 Nanoparticles Using Solid State Reaction Method

ITO (In0.95Sn0.05)(2)O-3 and Ni doped ITO (In0.90Sn0.05Ni0.05)(2)O-3 nanoparticles (NPs) were synthesized by solid state reaction method and subjected to study their structural, optical and magnetic properties. The NPs had a size distribution in the range of 40 nm and were identified as the bcc cubic In2O3 by X-ray diffraction (XRD). Optical properties of the samples were studies using UV-Vis-NIR spectrophotometer. Magnetic measurements were carried out at room temperature and at 100 K using vibrating sample magnetometer and found that the ITO nanoparticles were ferromagnetic in nature at room temperature. The strength of the magnetization decreased in ITO nanoparticles when the magnetic measurements carried out at 100 K

Ferromagnetic and Photoluminescence Properties of Fe doped Indium-Tin- Oxide Nanoparticles Synthesised by Solid State Reaction

International audienceIron and tin codoped indium oxide (In0.90Sn0.05Fe0.05)2O3) nanoparticles were synthesized by solid state reaction. The synthesized nanoparticles were studied for their structural, surface, chemical, optical, magnetic and photoluminescence properties using respective characterization techniques. The XRD and FE-SEM images confirmed the nanosize of the particles. Raman studies indicated no structural changes in the indium oxide lattice after addition of Fe and Sn into the lattice. From magnetic studies it was observed that the Sn doped indium oxide nanoparticles were ferromagnetic. The ferromagnetic nature is destroyed after codoping of iron and tin in indium oxide lattice. Two broad emission peaks were observed in photoluminescence spectra. Introduction. Currently the dilute magnetic semiconducting (DMS) materials are finding increased interest due to their potential as well as practical applications in the field of spintronics as well as exhibiting ferromagnetism at or above room temperature [1-4]. Till now many transition metal doped oxide semiconductors such as ZnO, TiO2, CeO2 and In2O3 were found to be exhibiting ferromagnetism at room temperature[5-7]. Among them, Indium oxides (In2O3) have high density of charge carriers, optical transparency and have low impact on the environment. Previous reports suggest that the decrease in crystal size of these oxides in the range of nanoparticles can lead to the change in their physical, chemical and optical properties [8, 9]. The decrease in crystal size can occur by doping the host lattice with another lattice having less ionic radii than the host. So In2O3 is doped with Sn as ionic radii of Sn is less than In. This leads to the formation of one of the best transparent conductive oxides (TCOs) namely indium-tin oxide (ITO). Generally, it has a lattice parameter of a = 10.118 Å[10]. Consequently, ITO has high optical transparency, high electrical conductivity and high reflectance. ITO in the form of films has been used as transparent electrodes for flat-panel displays, electrochromic windows, solar panels and transparent coatings for solar-energy heat mirrors [11-14]. A large number of articles regarding transition metal doped In2O3 thin films have been published but there are rarely any reports on magnetic and photoluminescence properties of transition metal and tin codoped indium oxide nanoparticles having uniform sized particles [15, 16]

Structural, Optical and Magnetic Properties of Co doped ZnSe Powders

International audienceCo doped ZnSe nano crystalline powder samples were prepared by solid-state reaction method.Structural, optical and magnetic properties of pure and Co doped ZnSe powders were studied. Both Pure and doped ZnSe samples were in cubic structure. Lattice parameter and band gap of pure and doped ZnSe powders decreased with increase of Co concentration. The Raman shift in the Raman spectra of the samples confirms the Co doping in to the ZnSe lattice.Band gap of the samples decreased with increase of Co concentration. Codoped ZnSe powders exhibited half-metallic ferromagnetism at room temperature with low Co concentration and paramagnetism with high Co concentration. Introduction.Dilute magnetic semiconductors (DMS) have earned good interest in recent years because of its feasibility to have magnetic and semiconducting properties in the same materials.DMS materials are the traditional non-magnetic semiconductors doped with transition metal or rare earth metal ions at very low concentration. The host material is exhibiting some peculiar properties after doping with suitable transition metal ions[1]. DMS materials find more attention because of their applications inopto-electronics and spintronics devices, which utilizesboth the spin and charge of the electrons[2, 3]. Further these find significant role in designing of spin valves, spin light emitting diodes and ultra-fast optical switches[4]. Extensive studies had been carriedout on several II-VI DMS compounds.Among all II-VI semiconductors, ZnSe is a potential candidate to fit in various applications as solar cells [5], bio-medical tags [6]and light emitting diodes [7].ZnSe is a blue-lasing material and can be employed in designing modulated hetero structures and optical wave guides[8]. Doping magnetic ions of +2 oxidation state into II-VI DMS such as CdSe, CdTe and ZnSe is easy.Co is one of the suitable ferromagnetic transition metal to dope in to II-VI semiconductors. Different model or mechanisms such as double exchange, RKKY carrier induced intractions, super-exchange were applied to explain the origin of ferromagnetism in these II-VI DMS compounds [9, 10]. The present work focus on the effect of Co doping concentration on structural, optical and magnetic properties of Co doped ZnSe powders

Structural, Optical and Magnetic Properties of Cr Doped CdSe Powders Prepared by Solid State Reaction

International audienceAs the key factor to study dilute magnetic semiconductors (DMS) for spintronic applications is the potential to harvest high-quality-single-phase dilute magnetic semiconductors. In this paper, we report the room temperature ferromagnetism (RTFM) in Cr doped CdSe powders synthesized through solid state reaction. The structural, optical and magnetic properties of Cd1-xCrxSe (x= 0.00, 0.04 and 0.08) powders at room temperature has been investigated. X-ray diffraction (XRD) studies confirmed the chromium (Cr) incorporation into the CdSe crystal lattice without disturbing the hexagonal (wurtzite) structure. The lattice parameters are found to be increased with increased Cr concentration in CdSe lattice. The band gap of Cd1-xCrxSe powders has been found to be red shifted as compared to pure CdSe. Magnetic hysteresis (M-H) loops at room temperature reveal the persistence of ferromagnetism in Cd1-xCrxSe powders. The saturation magnetization values increased with increase of 'x' in Cd1-xCrxSe. The observed RTFM might due to carrier mediated exchange interactions present in the system. Introduction. The novel combination of material properties such as room temperature ferromagnetism and semiconducting behavior has spawned interest in spin current injection for storage devices. Dilute magnetic semiconductors (DMS) are traditional semiconductors in which magnetic transition metal impurities with partially filled 'd' statesand lanthanide series elements with partially filled 'f' shell electrons replace cations of the host semiconducting materials. DMS are assumed to be potential resources for practical spintronic based devices [1-3]. It is an exciting field of research wherein both the charge and spin are used for transportation, storage and processing of information in a single spintronic device [4].Room temperature ferromagnetism (RTFM) is an essential property for DMS materials. In order to acquire RTFM in DMS materials, transition metal (Fe, Ni, Co, Mn, Cr) has been doped in different semiconductors such as ZnO [5], GaN [5], TiO2 [6], CdS [7], CdSe [8] and SnO2 [9]. II-VI and III-V DMS offer unique combination of structural, electronic and magnetic properties, which strongly depends on the nature and concentration of the dopant. The transition metals find greater solubility in II–VI compound semiconductors, when compared with III-VI semiconductors[10] .Till date extensive reports are available on nitride, oxide and chalcogenide DMS with different theories and mechanisms explaining the interactions such as double exchange, super-exchange and RKKY type in both the theoretical and experimental aspects with conflicting results on room temperature ferromagnetism. Yet, the origin of observed magnetism in DMSs is still a topic of debate[11, 12]. Apart from this, various reasons for the observed magnetis

Structural and Magnetic Properties of Ni Doped S

Nickel (Ni) doped SnO2 powder samples were prepared using solid-state reaction with dopant concentrations in the range of 3 at.% to 15 at.%. The influence of Ni doping on structural, optical, and magnetic properties of the powder samples has been investigated. All the Ni doped powder samples exhibited tetragonal structure of SnO2. A decrease in optical band gap was observed with increase of Ni doping levels. The vibrating sample magnetometer measurements revealed that the Ni doped SnO2 powder samples were ferromagnetic at room temperature