Magnetically Soft Co-C Granular-like Amorphous Thin Films With High Resistivity and High Saturation Flux Density

2002 ◽  
Vol 721 ◽  
Author(s):  
H. Wang ◽  
S.P. Wong ◽  
M.F. Chiah ◽  
W.Q. Li ◽  
C.Y. Poon ◽  
...  
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Electrical Transport ◽  
Quantum Interference ◽  
Rutherford Backscattering Spectrometry ◽  
Magnetic Hysteresis ◽  
High Resistivity ◽  
Vacuum Furnace ◽  
Electrical Transport Properties ◽  
X Ray

AbstractGranular-like amorphous CoxC1-x nanocomposite thin films, with x in the range of 60-75% in atomic percentage, have been prepared by pulsed filtered vacuum arc deposition. The structures of the films were characterized by non-Rutherford backscattering spectrometry, transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and Raman spectroscopy. The in-plane magnetic hysteresis loops were measured by a superconducting quantum interference device magnetometer at room temperature. The electrical transport properties were measured by the four-probe technique at various temperatures ranging from 20 to 300 K. The films were found to be magnetically soft with coercivities in the range of 2 to 12 Oe, resistivities in the range of 130 to 300 μΩcm, and magnetic saturation flux densities in the range of 6 to 13 kG. The films also showed good thermal stability in their structural, electrical and magnetic properties upon annealing up to 200°C in a vacuum furnace.

Superparamagnetic Behavior of Granular Co-C Films Consisting of Nanocrystalline Cobalt Encapsulated in Carbon

2000 ◽  
Vol 614 ◽  
Author(s):  
Hao Wang ◽  
S.P. Wong ◽  
W.Y. Cheung ◽  
N. Ke ◽  
M.F. Chiah ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Rutherford Backscattering Spectrometry ◽  
Magnetic Measurements ◽  
Magnetic Hysteresis ◽  
Blocking Temperature ◽  
Vacuum Arc ◽  
Zero Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy

ABSTRACTNanocomposite Co-C thin films of about 15 nm thick were prepared by pulsed filtered vacuum arc deposition. The films were characterized by x-ray photoelectron spectroscopy, non-Rutherford backscattering spectrometry, x-ray diffraction, magnetic force microscopy and magnetic measurements. The as-deposited films were amorphous. After annealing at 350°C for one hour in vacuum (< 10−3 Pa), the films were found to consist of nanocrystalline Co grains encapsulated in carbon. The superparamagnetism of the annealed Co36C64 film was demonstrated by the measurement of DC susceptibility and magnetic hysteresis using a SQUID magnetometer. The superparamagnetic relaxation blocking temperature was marked to be about 12K by the peak of the zero-field-cooled magnetization under a field of 100 Oe. The magnetic properties of these annealed granular Co-C films transform from superparamagnetism to ferromagnetism when the Co concentration increases.

Influence of the Microstructure on the Optical Characteristics of SrTiO3 thin films

2005 ◽  
Vol 20 (1) ◽  
pp. 68-74 ◽  
Author(s):  
M. Gaidi ◽  
L. Stafford ◽  
A. Amassian ◽  
M. Chaker ◽  
J. Margot ◽  
...  
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Rutherford Backscattering Spectrometry ◽  
Optical Characteristics ◽  
Silicon Substrates ◽  
Deposition Pressure ◽  
X Ray ◽  
Full Characterization

The influence of the microstructure of strontium-titanate-oxide (SrTiO3 or STO) thin films on their optical properties was investigated through an extensive characterization. The STO films have been deposited on silicon substrates by reactive pulsed laser deposition. The effect of the oxygen deposition pressure on the crystalline quality of the films was systematically studied by x-ray diffraction and scanning electron microscopy. Rutherford backscattering spectrometry, x-ray photoelectron spectroscopy, and secondary ion mass spectrometry were used to determine the atomic density and depth concentration profiles of the various species forming the film. The refractive index and extinction coefficient were obtained using variable angle spectroscopic ellipsometry. Based on this full characterization, it is demonstrated that the optical characteristics of the films are directly correlated to their microstructural properties. In particular, the refractive index increases with film density, while losses decrease. In addition, the interface between STO and Si is characterized by an interdiffusion layer. As the deposition pressure is enhanced, the width of this layer significantly increases, inducing localized inhomogeneity of the refractive index.

Synthesis of Nb-doped TiO2 films on rigid and flexible substrates at low temperature

2019 ◽  
Vol 33 (26) ◽  
pp. 1950313 ◽  
Author(s):  
Kashif Safeen ◽  
V. Micheli ◽  
R. Bartali ◽  
G. Gottardi ◽  
Akif Safeen ◽  
...  
Keyword(s):  
Crystallite Size ◽  
Photoelectron Spectroscopy ◽  
Electrical Transport ◽  
Flexible Substrate ◽  
Nir Spectroscopy ◽  
Hall Effect Measurement ◽  
Visible Range ◽  
Silicon Substrates ◽  
Electrical Transport Properties ◽  
X Ray

In this work, an attempt has been made to compare the physical properties of conductive films of Nb-doped TiO2 deposited on Kapton polyimide, glass and silicon substrates. Thin films were deposited by radio frequency sputtering at room temperature and subsequently characterized using X-ray diffraction, X-ray photoelectron spectroscopy, UV-VIS-NIR spectroscopy and Hall Effect measurement. Structurally, the films grown on the flexible substrate exhibit more strain and had inferior crystallinity (crystallite size [Formula: see text]13.8 nm) compared to the films deposited on glass and silicon substrates (crystallite size [Formula: see text]27 nm). The film on glass had a resistivity value around [Formula: see text] while the resistivity of the films grown on polyimide was found about five-fold higher. Furthermore, the films deposited on glass substrate showed optical transparency of [Formula: see text]80% in the visible range (400–750 nm). The inferior electrical transport properties of the films grown on polyimide were correlated with the poor crystallinity and cracks induced during the annealing process. Furthermore, various possible routes have been discussed to improve crystallinity and control cracks in the films.

scholarly journals Preparation and Characterization ofSb2Te3Thin Films by Coevaporation

2010 ◽  
Vol 2010 ◽  
pp. 1-4 ◽  
Author(s):  
Bin Lv ◽  
Songbai Hu ◽  
Wei Li ◽  
Xia Di ◽  
Lianghuan Feng ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Photoelectron Spectroscopy ◽  
Electrical Transport ◽  
Film Surface ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Conductivity Measurements ◽  
X Ray ◽  
Thin Film Surface

Deposition ofSb2Te3thin films on soda-lime glass substrates by coevaporation of Sb and Te is described in this paper.Sb2Te3thin films were characterized by x-ray diffraction (XRD), x-ray fluorescence (XRF), atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), electrical conductivity measurements, and Hall measurements. The abnormal electrical transport behavior occurred fromin situelectrical conductivity measurements. The results indicate that as-grownSb2Te3thin films are amorphous and undergo an amorphous-crystalline transition after annealing, and the posttreatment can effectively promote the formation of Sb-Te bond and prevent oxidation of thin film surface.

Crystal structures and magnetic properties of Fe–N thin films deposited by dc magnetron sputtering

2004 ◽  
Vol 19 (4) ◽  
pp. 352-355 ◽  
Author(s):  
Wei Tao Zheng ◽  
Xin Wang ◽  
Xianggui Kong ◽  
Hongwei Tian ◽  
Shansheng Yu ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Magnetron Sputtering ◽  
Crystal Structures ◽  
Photoelectron Spectroscopy ◽  
Quantum Interference ◽  
Flow Ratio ◽  
Dc Magnetron Sputtering ◽  
X Ray ◽  
Glass Substrates

Fe–N thin films were deposited on glass substrates by dc magnetron sputtering under various Ar∕N2 discharge conditions. Crystal structures and elemental compositions of the films were characterized by X-ray diffraction and X-ray photoelectron spectroscopy. Magnetic properties of the films were measured using a superconducting quantum interference device magnetometer. Films deposited at different N2∕(Ar+N2) flow ratios were found to have different crystal structures and different nitrogen contents. When the flow ratios were 60%, 50%, and 30%, a nonmagnetic single-phase FeN was formed in the films. At the flow ratio of 10%, two crystal phases of γ′-Fe4N and ε-Fe3N were detected. When the flow ratio reduced to 5%, a mixture of α-Fe, ε-Fe3N, FeN0.056, and α″-Fe16N2 phases was obtained. The value of saturation magnetization for the mixture was found to be larger than that of pure Fe.

Effect of Sputtering Input Power of Co on Structure and Magnetic Properties of Fe-Co-N Thin Films

2009 ◽  
Vol 79-82 ◽  
pp. 635-638 ◽  
Author(s):  
Xin Wang ◽  
Hui Jia ◽  
Wei Tao Zheng ◽  
Wei Xu ◽  
Bei Hong Long
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Quantum Interference ◽  
Input Power ◽  
Superconducting Quantum Interference Device ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Composition Structure

Fe-Co-N thin films with various Co content were synthesized on Si (111) substrate using facing-target magnetron sputtering by changing sputtering input power on Co target. During deposition, the input power on Fe target was kept at 160 W. The composition, structure, and magnetic properties were examined by X-ray photoelectron spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and superconducting quantum interference device. XRD and TEM investigations showed that at lower input power of 11.2 W on Co target, the phases in the film were -(Fe,Co)4N and Co3N. Increasing sputtering input power, the content of Co in the film increased. At input power of 14 W, film contained -(Fe,Co)8N phase was produced which exhibited higher saturation magnetization (252.85 Am2/kg) and lower value of coercivity (3.66 kAm-1), corresponded to the 12% content of Co in the film.

scholarly journals A Comparative Study of Structural, Optical and Electrical Properties of Fe-ZnO Nanoparticles Synthesized by Precipitation and Microwave Method for Photovoltaic Applications

2021 ◽  
Vol 03 (03) ◽  
pp. 1-1
Author(s):  
Ganga R. Neupane ◽  
◽  
Amrit Kaphle ◽  
David N. Mcllroy ◽  
Elena Echeverria ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Structural Properties ◽  
Zno Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Electrical Transport ◽  
Precipitation Method ◽  
Microwave Method ◽  
Optical And Electrical Properties ◽  
Electrical Transport Properties ◽  
X Ray

Iron doped ZnO (Fe-ZnO) nanoparticles were synthesized using two techniques that are economical as well as scalable to yield tunable properties of nanoparticles for facilitating down conversion in an absorbing layer of a solar cell. To evaluate the suitability of Fe-ZnO nanoparticles prepared by two deposition methods, we present a comparison of optical, electrical, and structural properties of Fe-ZnO using several experimental techniques. Structural properties were analyzed using transmission electron microscopy and x-ray diffraction spectroscopy (XRD) with Rietveld analysis for extracting information on compositional variations with Fe doping. The chemical composition of nanoparticles was analyzed through X-ray photoelectron spectroscopy (XPS). The optical properties of nanoparticles were studied using photoluminescence and UV-Vis absorption spectroscopy. In addition, fluorescence lifetime measurement was also performed to study the changes in an exponential decay of lifetimes. The electrical transport properties of Fe-ZnO were analyzed by impedance spectroscopy. Our studies indicate that ethanol as a solvent in a microwave method would produce smaller nanoparticles up to the size of 11 nm. In contrast, the precipitation method produces secondary phases of Fe2O3 beyond 5% doping. In addition, our studies show that the optical and electrical properties of resulting Fe-ZnO nanoparticles depend on the particle sizes and the synthesis techniques used. These new results provide insight into the role of solvents in fabricating Fe-ZnO nanoparticles by precipitation and microwave methods for photovoltaic and other applications.

Structure, Magnetic and Transport Properties of MnxGe1-x

2008 ◽  
Vol 47-50 ◽  
pp. 570-574
Author(s):  
Shuang Qiao ◽  
Deng Lu Hou ◽  
Qian Zhang ◽  
Cong Mian Zhen
Keyword(s):  
Transport Properties ◽  
Photoelectron Spectroscopy ◽  
Electrical Transport ◽  
Deep Level ◽  
Magnetic Domain ◽  
Secondary Phase ◽  
Electrical Transport Properties ◽  
X Ray ◽  
Increasing Temperature ◽  
Mn Concentration

Ge1-xMnx (x=0.05, 0.07, 0.11, 0.15, 0.19, 0.23, 0.26, 0.29) thin films were prepared by magnetron sputtering. All the films had a Ge cubic structure, and no indication of a secondary phase was found in any sample using X-ray diffraction (XRD). The crystal lattice constant increases with the Mn concentration, in accordance with Vegard's law. No films show clear magnetic domain structure under a magnetic force microscope (MFM). Atom force microscope (AFM) measurements show that all films have a uniform particle size distribution, and a columnar growth pattern. X-ray photoelectron spectroscopy (XPS) measurements indicate that the Mn atoms are not singlely in the bivalent. Electrical transport properties show that the resistance of the films increases with increasing Mn concentration, suggesting that the Mn ions are in deep-level acceptor states, while resistance decreases with increasing temperature, which is a typical semiconductor property.

scholarly journals Structural and Electrical Transport Properties of CdS and Al-doped CdS Thin Films Deposited by Spray Pyrolysis

2011 ◽  
Vol 4 (1) ◽  
pp. 11 ◽  
Author(s):  
A. H. Rubel ◽  
J. Podder
Keyword(s):  
Thin Films ◽  
Cadmium Sulfide ◽  
Spray Pyrolysis ◽  
Electrical Transport ◽  
Electrical Measurement ◽  
Hexagonal Structure ◽  
Electrical Transport Properties ◽  
X Ray ◽  
Cds Thin Films ◽  
Cds Film

Cadmium sulfide (CdS) and aluminum (Al) doped cadmium sulfide (Cd1-xAlxS) thin films have been deposited on glass substrate at 300 ºC by spray pyrolysis. The structural and electrical properties of the as-deposited films have been characterized using Energy Dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) and D.C. electrical measurement. The effect of Al on the surface morphology of CdS film was studied by Scanning Electron microscopy (SEM). EDX shows that the deposited samples are stoichiometric. The peak intensities observed in the XRD patterns were found consistent to a polycrystalline hexagonal structure. The XRD study shows that the hexagonal structure of CdS is not much affected with respect to Al doping.  Al-doped CdS thin films show low electrical resistivity of about 48 Ω cm and high carrier density of about 1.1×1019 cm-3.Keywords: Spray pyrolysis; CdS, Cd1-xAlxS; Thin films; EDX; XRD; Hall mobility.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.8548J. Sci. Res. 4 (1), 11-19  (2012) 

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