Laser Ablated CuCo Thin Films Exhibiting Controlled Anisotropic Giant Magnetoresistance

1998 ◽  
Vol 526 ◽  
Author(s):  
Vicente Madurga ◽  
J. Vergara ◽  
R.J. Ortega ◽  
K.V. Rao
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Giant Magnetoresistance ◽  
Nominal Composition ◽  
Target Speed ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Speed Rotation ◽  
Co Nanoparticles ◽  
Pure Cu

AbstractControlled microstructured thin films with nominal composition Cu95Co5 have been deposited on glass substrates by pulsed laser ablation at room temperature, in vacuum, for different target speed rotation. Atomic Force Microscopy, AFM, studies have shown a surface roughness not higher than 0.5 nm, for the as-deposited samples, which do not exhibit magnetoresistive, MR, behaviour. X-ray diffraction analysis show broad diffraction peaks, slightly shifted from pure Cu reflection peaks. After annealing, the samples show GMR. The AFM investigations reveal a surface roughness of =6.8 nm and =9.2 nm for the samples prepared with high and low target speed rotation, respectively. Furthermore the GMR data correspond to a strong anisotropic behaviour. A reversible MR is exhibited, for all the films, exclusively for perpendicular to the films plane applied magnetic field. Hysteretic MR behaviour is observed for any other direction: in the range of 70-80 deg., coercive MR fields from 0.17 Tesla to 0.05 Tesla are observed for the samples obtained at 10 rpm to 32 rpm respectively target speed rotation. These properties are discussed in terms of the shape anisotropy of magnetic Co nanoparticles.

WO3:Mo and WO3:Ti Thin Films Deposited by Spray Pyrolysis: The Influence of Metallic Concentration on Physical Properties: An Electron Microscopy and Atomic Force Study

2019 ◽  
Vol 286 ◽  
pp. 49-63
Author(s):  
Dwight Acosta ◽  
Francisco Hernández ◽  
Alejandra López-Suárez ◽  
Carlos Magaña
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Ultra Violet ◽  
Surface Characteristics ◽  
Structural Defects ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Transmission Electron ◽  
Resolution Electron

WO3:Mo and WO3:Ti thin films have been deposited on FTO/Glass substrates by the pulsed chemical spray technique at a substrate temperature of Ts= 450°C. The influence of Mo and Ti doping on the structural, electrical, and optical behavior of WO3thin films, has been studied by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), Ultra Violet and Visible Spectrometry (UV-VIS), and Surface Conductivity Methods (Four Points). Doped WO3films presents similar polycrystalline structures but with noticeable modifications in surface configurations at micrometric and nanometric levels, as the Mo and Ti concentration is systematically increased in the starting sprayed solution. From processed High-Resolution Electron Micrographs (HREM), a low density of structural defects was found on pure and doped WO3grains. This lead to conclude that variations in films surface characteristics are mainly related with metallic doping concentrations which in turn, have noticeable influence in electrical and optical behaviors reported in this work.

scholarly journals Growth and Characterization of (Tb,Yb) Co-Doping Sprayed ZnO Thin Films

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 169 ◽  
Author(s):  
A. El hat ◽  
I. Chaki ◽  
R. Essajai ◽  
A. Mzerd ◽  
G. Schmerber ◽  
...  
Keyword(s):  
Thin Films ◽  
Secondary Phase ◽  
Hexagonal Wurtzite Structure ◽  
Zno Thin Films ◽  
Spray Pyrolysis Method ◽  
Efficient Energy Transfer ◽  
Force Microscopy ◽  
Co Doping ◽  
Glass Substrates ◽  
Hall Effect Measurements

Structural, optical and electrical properties of (ytterbium/terbium) co-doped ZnO thin films deposited on glass substrates using the spray pyrolysis method were investigated. The films exhibited the hexagonal wurtzite structure with a preferential orientation along (002) direction. No secondary phase was observed in the X-ray diffraction detection limit. Atomic force microscopy (AFM) was performed and root means square roughness (RMS) of our samples decreased with terbium content. Photoluminescence measurements showed a luminescence band at 980 nm which is characteristic of Yb3+ transition between the electronic levels 2F5/2 to 2F7/2. This is experimental evidence for an efficient energy transfer from the ZnO matrix to Yb. Hall Effect measurements gave a low electrical resistivity value around 6.0 × 10−3 Ω.cm. Such characteristics make these films of interest to photovoltaic devices.

scholarly journals Investigating the Nanocomposite Thin Films of Hematite α-Fe2O3 and Nafion for Cholesterol Biosensing Applications

2020 ◽  
Vol 2 ◽  
Author(s):  
Indra Sulania ◽  
R. Blessy Pricilla ◽  
G. B. V. S. Lakshmi
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Differential Pulse ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Enzyme Substrate ◽  
Atomic Force ◽  
Nanocomposite Thin Films ◽  
Multi Phase ◽  
Cholesterol Biosensor

Nanocomposite materials are multi-phase materials, usually solids, which have two or more component materials having different chemical and physical properties. When blended together, a newer material is formed with distinctive properties which make them an eligible candidate for many important applications. In the present study, thin films of nafion (polymer) and hematite or α-Fe2O3 (nanoparticles) nanocomposite is fabricated on indium tin oxide (ITO) coated glass substrates, due to its enhanced ionic conductivity, for cholesterol biosensor applications. Scanning electron microscopy and Atomic force microscopy revealed the formation of nanorod structured α-Fe2O3 in the films. The cyclic voltammetry (CV) studies of nafion-α-Fe2O3/ITO revealed the redox properties of the nanocomposites. The sensing studies were performed on nafion-α-Fe2O3/CHOx/ITO bioelectrode using differential pulse voltammetry (DPV) at various concentrations of cholesterol. The enzyme immobilization leaded to the selective detection of cholesterol with a sensitivity of 64.93 × 10−2 μA (mg/dl)−1 cm−2. The enzyme substrate interaction (Michaelis–Menten) constant Km, was obtained to be 19 mg/dl.

Synthesis and Characterization of Nb-Doped TiO2 Thin Films Prepared by RF Magnetron Sputtering

2015 ◽  
Vol 1117 ◽  
pp. 139-142 ◽  
Author(s):  
Marius Dobromir ◽  
Radu Paul Apetrei ◽  
A.V. Rogachev ◽  
Dmitry L. Kovalenko ◽  
Dumitru Luca
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Rf Magnetron Sputtering ◽  
X Ray ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Diffraction Patterns

Amorphous Nb-doped TiO2 thin films were deposited on (100) Si and glass substrates at room temperature by RF magnetron sputtering and a mosaic-type Nb2O5-TiO2 sputtering target. To adjust the amount of the niobium dopant in the film samples, appropriate numbers of Nb2O5 pellets were placed on the circular area of the magnetron target with intensive sputtering. By adjusting the discharge conditions and the number of niobium oxide pellets, films with dopant content varying between 0 and 16.2 at.% were prepared, as demonstrated by X-ray photoelectron spectroscopy data. The X-ray diffraction patterns of the as-deposited samples showed the lack of crystalline ordering in the samples. Surfaces roughness and energy band gap values increase with dopant concentration, as showed by atomic force microscopy and UV-Vis spectroscopy measurements.

Study of surface roughness for thin films of CaF2 deposited on glass substrates

1983 ◽  
Vol 46 (5-6) ◽  
pp. 294-299 ◽  
Author(s):  
G. Rasigni ◽  
F. Varnier ◽  
J.P. Palmari ◽  
N. Mayani ◽  
M. Rasigni ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Glass Substrates

ZnO Films Deposited on Various Diamond Film Substrates with Different Surface Roughness

2011 ◽  
Vol 287-290 ◽  
pp. 2347-2350
Author(s):  
Rong Fan ◽  
Lin Jun Wang ◽  
Jian Huang ◽  
Ke Tang ◽  
Ji Jun Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Diamond Film ◽  
Zno Thin Films ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Free Standing ◽  
Axis Orientation ◽  
X Ray ◽  
Force Microscopy

ZnO thin films were deposited by radio frequency (R. F.) magnetron sputtering on various diamond film substrates with different surface roughness. The influence of surface roughness on structural properties and surface morphology of ZnO thin films was investigated by X-ray diffraction (XRD) and atom force microscopy (AFM), respectively. Only on the nanocrystalline and free-standing diamond substrates, ZnO films with preferential c-axis orientation and smooth surface were obtained.

scholarly journals The Effect of Film Thickness on the Structural Properties of Vacuum Evaporated Poly(3-methylthiophene) Thin Films

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Sandip V. Kamat ◽  
Vijaya Puri ◽  
R. K. Puri
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Surface Roughness ◽  
Surface Morphology ◽  
Film Thickness ◽  
Structural Properties ◽  
Vacuum Evaporation ◽  
Intrinsic Stress ◽  
Glass Substrates ◽  
Structure Surface

This paper reports on the structural properties of poly(3-methylthiophene) P3MeT thin films prepared by vacuum evaporation on the glass substrates. The structural and surface morphology, wettability, adhesion, and intrinsic stress of these thin films were studied for three different thicknesses. The variation of the film thickness affects the structure, surface, and mechanical properties of P3MeT thin films. Vapor chopping also strongly influences the surface morphology, surface roughness, and wettability of the thin films. It was found that there is a decrease in the intrinsic stress and (RMS) roughness, while the adhesion increases with increase in film thickness.

Structural and Optical Properties of PbI2 Thin Films to Fabricate Perovskite Solar Cells

2020 ◽  
Vol 398 ◽  
pp. 140-146
Author(s):  
Kawther A. Khalaph ◽  
Zainab J. Shanan ◽  
Aqel Mashot Jafar ◽  
Falah Mustafa Al-Attar
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Energy Gap ◽  
Perovskite Solar Cells ◽  
Lead Iodide ◽  
Structural And Optical Properties ◽  
Solar Cell Application ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force

Recently, lead iodide is the most materials employment in the perovskite solar cell application. This paper has studied the character of preparation, structural and optical properties of pbI2 materials. Structural properties are included investigation of the measurements X-Ray Diffraction (XRD), Scan Electron Microscopy (SEM), Fourier Transform InfraRed spectroscopy (FTIR) and Atomic Force Microscopy (AFM) tests to the PbI2 thin films samples. Optical properties are included the investigation UV-Vis test of the thin film samples deposited on glass substrates and investigated the Absorption, Transmittance and evaluated energy gap (Eg = 2.3 eV).

THICKNESS DEPENDENCE OF THIRD-HARMONIC GENERATION FROM SELF-ASSEMBLED REGIOREGULAR POLY(3-HEXYLTHIOPHENE) THIN FILMS ON QUARTZ GLASSES WITH DIFFERENT SURFACES

2008 ◽  
Vol 17 (04) ◽  
pp. 451-463 ◽  
Author(s):  
XIN WANG ◽  
JIASHENG RU ◽  
SHIZUYASU OCHIAI ◽  
YUU YAMADA ◽  
YOSHIYUKI UCHIDA ◽  
...  
Keyword(s):  
Thin Films ◽  
Visible Absorption ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Cast Films ◽  
Regioregular Poly ◽  
Out Of Plane ◽  
Self Assembled ◽  
Quartz Glasses

Regioregular poly(3-hexylthiophene) [RR-P3HT] thin films were prepared on fused quartz glasses by spin-coating and drop-casting from the chloroform solutions. Film structures and morphologies were characterized by UV-visible absorption spectra, out-of-plane X-ray diffraction (XRD) and atomic force microscopy (AFM). Drop-cast films showed increased χ(3) of about three times higher than that of the spin-coated ones when the film thicknesses were both around 140 nm, and the magnitude of the increase was different for different thickness. The magnitudes of χ(3) for drop-cast RR-P3HT films were calculated in the range of 10-11 esu, and the phases of χ(3) lay in the range from 230 to 300° which were consistent with the contributions from two-photon absorptions (TPA). Hexamethyldisilazane (HMDS) treatment of the glass substrates could increase the χ(3) of drop-cast films further from about ten percent to several times higher. This also depended on the film thickness. These results revealed the deposition method and surface modification effects on the self-assembled RR-P3HT film structures, and the importance of higher-ordering and increased crystallinity for the enhancement of the χ(3) of the polymeric films for their applications in NLO devices.

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