Loading...
Search for: magnetrons
0.01 seconds
Total 31 records

    Partly semiconductor covered vane fast magnetron

    , Article IEEE Transactions on Plasma Science ; Volume 50, Issue 5 , 2022 , Pages 1179-1187 ; 00933813 (ISSN) Hashemi, S. M. A ; Hashemi, S. M. A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2022
    Abstract
    Alterations in the structure of a magnetron, e.g., the A6 relativistic magnetron, are proposed, which considerably increase the device's build-up speed. We cover the magnetron vane surfaces with semiconductor layers of nonzero electric conductivity, with an exact geometrical design. Semiconductor layers with considerable mechanical strength also provide excellent shielding for the vanes against the high-energy relativistic electrons' bombardment. The novel structure introduces several new free parameters to the magnetron design procedure and considerably increases the design flexibility. A multistage exact optimization procedure, performed by extensive computer simulations, shows that... 

    Formation of gold nanoparticles in heat-treated reactive co-sputtered Au-SiO 2 thin films

    , Article Applied Surface Science ; Volume 254, Issue 1 SPEC. ISS , 2007 , Pages 286-290 ; 01694332 (ISSN) Sangpour, P ; Akhavan, O ; Moshfegh, A. Z ; Roozbehi, M ; Sharif University of Technology
    Elsevier  2007
    Abstract
    In this work, formation of gold nanoparticles in radio frequency (RF) reactive magnetron co-sputtered Au-SiO 2 thin films post annealed at different temperatures in Ar + H 2 atmosphere has been investigated. Optical, surface topography, chemical state and crystalline properties of the prepared films were analyzed by using UV-visible spectrophotometry, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and X-ray diffractometry (XRD) techniques, respectively. Optical absorption spectrum of the Au-SiO 2 thin films annealed at 800 °C showed one surface plasmon resonance (SPR) absorption peak located at 520 nm relating to gold nanoparticles. According to XPS analysis, it was... 

    Effect of Cathode Voltage Waveform on the Output Power of Magnetrons

    , M.Sc. Thesis Sharif University of Technology Zarghani, Mostafa (Author) ; Kaboli, Shahriyar (Supervisor)
    Abstract
    In industial applications such as linear accelerators, pulsed lasers, nuclear fusion, radar systems, medical applications and etc. that need great ratio of instantanuse to the average power, pulsed power supplies are used. These power supplies store energy in an energy storage element and discharge this energy to load in a short period of time. The most important characterisitics of them are output pulse quality, reliability and longevity of the resource, efficiency and cost. One of the devices that produce high instantaneous RF power is magnetron tube. In some applications such as radar systems, quality of the output RF is very important and the most important factor that affect the quality... 

    Comparison between decolorization of denim fabrics with Oxygen and Argon glow discharge

    , Article Surface and Coatings Technology ; Volume 201, Issue 9-11 SPEC. ISS , 2007 , Pages 4926-4930 ; 02578972 (ISSN) Ghoranneviss, M ; Shahidi, S ; Moazzenchi, B ; Anvari, A ; Rashidi, A ; Hosseini, H ; Sharif University of Technology
    2007
    Abstract
    In this study, we have used a low temperature plasma, produced by a DC magnetron sputtering device, for decolorizing of denim fabrics, and the effect of using different gases such as Argon and Oxygen as the discharge medium have been investigated. The results obtained under equal periods of time have been compared and the effect of washing on the treated denims has been reported. © 2006 Elsevier B.V. All rights reserved  

    Investigation into the effect of substrate material on microstructure and optical properties of thin films deposited via magnetron sputtering technique

    , Article Ceramics International ; 2021 ; 02728842 (ISSN) Mashaiekhy Asl, J ; Nemati, A ; Hadi, I ; Mirdamadi, Sh ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    This study aims at investigating the effect of the substrate material on growth mechanism and also microstructure of Ta2O5 thin films. For this purpose, atomic force microscopy, scanning electron microscopy, and interferometry analyses were implemented to reveal the influence of silicon wafer and amorphous BK7 glass substrates on the nucleation and growth mechanisms of Ta2O5 thin films deposited via the radio frequency magnetron sputtering technique. Results indicated that those films with finer morphologies had relatively higher nucleation densities. Compared with BK7 glass substrate, crystals formed on the silicon wafer were shown to be finer and had lower mean areas in more nucleation... 

    Fabrication of BSCCO thin films using sputtering technique

    , Article Physica Status Solidi C: Conferences ; Volume 1, Issue 7 , 2004 , Pages 1895-1898 ; 16101634 (ISSN) Salamati, H ; Kameli, P ; Akhavan, M ; Sharif University of Technology
    2004
    Abstract
    Investigation of BSCCO 2223 phase formation in superconducting thin films of Bi-based cuprates deposited on MgO substrate is reported. A series of films were made by in situ dc-magnetron sputtering method and another series were made by ex situ rf-magnetron sputtering technique. Same target have been used in both technique. In the case of the ex situ method, the films were annealed for different period of time at 800°C, and in the case of in situ method, the films were deposited at different temperature substrate. The influence of annealing time and the temperature of the substrate on the quality and the phase formation for ex situ and in situ method have studied, respectively. The results... 

    Investigation of CeO2 buffer layer effects on the voltage response of YBCO transition-edge bolometers

    , Article IEEE Transactions on Applied Superconductivity ; Volume 26, Issue 3 , 2016 ; 10518223 (ISSN) Mohajeri, R ; Nazifi, R ; Wulff, A. C ; Vesaghi, M. A ; Grivel, J. C ; Fardmanesh, M ; Sharif University of Technology
    Abstract
    The effect on the thermal parameters of superconducting transition-edge bolometers produced on a single crystalline SrTiO3 (STO) substrate with and without a CeO2 buffer layer was investigated. Metal-organic deposition was used to deposit the 20-nm CeO2 buffer layer, whereas RF magnetron sputtering was applied to fabricate 150-nm-thick superconducting YBa2Cu3O7-δ (YBCO) thin film. The critical transition temperature for both of the YBCO films was 90 K, and the transition width was ∼1.9 K. The bolometers fabricated from these samples were characterized with respect to the voltage phase and amplitude responses, and the results were compared with that of simulations conducted by applying a... 

    Multi-target sputter deposition of Ni50Ti 50 - XHfx shape memory thin films for high temperature microactuator application

    , Article Sensors and Actuators, A: Physical ; Volume 121, Issue 2 , 2005 , Pages 543-548 ; 09244247 (ISSN) Sanjabi, S ; Cao, Y. Z ; Barber, Z. H ; Sharif University of Technology
    2005
    Abstract
    High temperature shape memory NiTiHf thin films with varying hafnium contents up to 28.7 at.% were fabricated by DC magnetron sputtering using simultaneous sputter deposition from separate elemental targets. The required film composition was achieved by adjusting the power ratio to the targets. The as-deposited films were amorphous; a post deposition annealing was performed at 550 °C to crystallize the films. Two-micron thick films were characterized by energy dispersive spectroscopy in a scanning electron microscope, temperature controlled X-ray diffraction, differential scanning calorimetry, and atomic force microscopy. The results showed that above 10 at.% Hf additions the transformation... 

    The effect of Si addition and Ta diffusion barrier on growth and thermal stability of NiSi nanolayer

    , Article Microelectronic Engineering ; Volume 85, Issue 3 , 2008 , Pages 548-552 ; 01679317 (ISSN) Kargarian, M ; Akhavan, O ; Moshfegh, A. Z ; Sharif University of Technology
    2008
    Abstract
    Formation and thermal stability of nanothickness NiSi layer in Ni(Pt 4 at.%)/Si(1 0 0) and Ni0.6Si0.4(Pt 4 at.%)/Si(1 0 0) structures have been investigated using magnetron co-sputtering deposition method. Moreover, to study the effect of Si substrate in formation of NiSi and its thermal stability, we have used Ta diffusion barrier between the Ni0.6Si0.4 layer and the Si substrate. Post annealing treatment of the samples was performed in an N2 environment in a temperature range from 200 to 900 °C for 2 min. The samples were analyzed by four point probe sheet resistance (Rs) measurement, X-ray diffraction (XRD) and atomic force microscopy (AFM) techniques. It was found that the annealing... 

    Aluminum coatings on cotton fabrics with low temperature plasma of argon and oxygen

    , Article Surface and Coatings Technology ; Volume 201, Issue 9-11 SPEC. ISS , 2007 , Pages 5646-5650 ; 02578972 (ISSN) Shahidi, S ; Ghoranneviss, M ; Moazzenchi, B ; Anvari, A ; Rashidi, A ; Sharif University of Technology
    2007
    Abstract
    In this article, we have studied the properties (especially water repellency) of cotton coated by a thin layer of aluminum. The process has been performed in a low temperature plasma medium, using a magnetron sputtering device. We have also investigated the effect of different gases such as argon and oxygen as the discharge medium on the properties of the obtained samples. The results which are exposure time dependent show a good repellent property for 30 min of treating in argon medium under the condition of our experiment. However, when O2 is used in the system, the cotton property changes to become hydrophilic of which the factor decreases as we increase the time of treating. © 2006... 

    Optical properties, microstructure, and multifractal analyses of ZnS thin films obtained by RF magnetron sputtering

    , Article Journal of Materials Science: Materials in Electronics ; Volume 31, Issue 7 , 2020 , Pages 5262-5273 Shakoury, R ; Arman, A ; Ţălu, Ş ; Ghosh, K ; Rezaee, S ; Luna, C ; Mwema, F ; Sherafat, K ; Salehi, M ; Mardani, M ; Sharif University of Technology
    Springer  2020
    Abstract
    The morphology, structure and optical properties of zinc sulfide (ZnS) thin films prepared through radio-frequency (RF) magnetron sputtering have been analyzed using atomic force microscopy (AFM), UV–Vis–NIR spectrophotometry, X-ray diffraction, and multifractal analyses. The X-ray diffraction patterns revealed that all ZnS thin films show a single peak at around 29.6°, which has been ascribed to the (111) planes of sphalerite phase, indicating that the growth direction of the films is the [111] direction. UV–Vis–NIR transmittance spectra were used to determine the refractive index of the samples, their thickness, and their band gap energy, showing the optical and semiconductor properties a... 

    Investigation into the effect of substrate material on microstructure and optical properties of thin films deposited via magnetron sputtering technique

    , Article Ceramics International ; Volume 48, Issue 5 , 2022 , Pages 6277-6286 ; 02728842 (ISSN) Mashaiekhy Asl, J ; Nemati, A ; Hadi, I ; Mirdamadi, S ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    This study aims at investigating the effect of the substrate material on growth mechanism and also microstructure of Ta2O5 thin films. For this purpose, atomic force microscopy, scanning electron microscopy, and interferometry analyses were implemented to reveal the influence of silicon wafer and amorphous BK7 glass substrates on the nucleation and growth mechanisms of Ta2O5 thin films deposited via the radio frequency magnetron sputtering technique. Results indicated that those films with finer morphologies had relatively higher nucleation densities. Compared with BK7 glass substrate, crystals formed on the silicon wafer were shown to be finer and had lower mean areas in more nucleation... 

    A Nonlinear Transmission Line Model for the Relativistic Magnetron

    , M.Sc. Thesis Sharif University of Technology Heyrani Nobari, Ali (Author) ; Farzaneh, Forouhar (Supervisor) ; Hashemi, Morad Ali (Co-Supervisor)
    Abstract
    Magnetron is one of the microwave-generating devices that operates based on the microwave-electron flow interaction in the active region of the tube, which is affected by the resonant cavities and It is used in a wide range of power (from kW range at home microwave ovens to several GW in relativistic high power magnetrons and the frequencies from the order of few too MHz to tens of GHz). Although nowday's low-power generators based on transistors have replaced microwave generating tubes and even MW radio transmitters are made based on the combination of semiconductor microwave generators, but in the production of RF pulses at higher frequencies and powers, the electron tubes are the main... 

    Sputter alloying of Ni, Ti and Hf for fabrication of high temperature shape memory thin films

    , Article Materials Science and Technology ; Volume 23, Issue 8 , 2007 , Pages 987-991 ; 02670836 (ISSN) Sanjabi, S ; Sadmezhaad, K ; Barber, Z. H ; Sharif University of Technology
    2007
    Abstract
    In the present paper, the fabrication and characterisation of typical high temperature Ni(Ti+ Hf) alloyed thin films produced by simultaneous sputter deposition from separate elemental Ni, Ti and Hf targets are presented. Film composition, determined by energy dispersive X-ray spectroscopy, was controlled by adjusting the ratio of powers applied to each target. Films deposited at room temperature had an amorphous structure and subsequent annealing at 550°C was carried out in a high vacuum environment, based on crystallisation temperature evaluation by differential scanning calorimetry (DSC). High temperature martensitic transformation, confirmed by DSC and variable temperature X-ray... 

    Adhesion modification of polyethylenes for metallization using radiation-induced grafting of vinyl monomers

    , Article Surface and Coatings Technology ; Volume 201, Issue 16-17 , 2007 , Pages 7519-7529 ; 02578972 (ISSN) Shojaei, A ; Fathi, R ; Sheikh, N ; Sharif University of Technology
    2007
    Abstract
    The present paper demonstrates the performance of the radiation grafting technique as a chemically based surface pretreatment method to adhesion modification of polyethylene surfaces toward the metallic layer. Gamma irradiation over a dose range of 4-10 kGy is used for grafting of vinyl monomers including acrylamide (AAm) and 1-vinyl-2-pyrrolidone (NVP) onto the surface of three different polyethylenes including low density polyethylene (LDPE) and two kinds of high density polyethylenes, namely HDPE-1 and HDPE-2. The grafting yield is evaluated based on the weight increase of the samples. It is found that the grafting yield is dominated by the crystallinity of the polyethylene, so that lower... 

    Growth and characterization of TixNi1-x shape memory thin films using simultaneous sputter deposition from separate elemental targets

    , Article Thin Solid Films ; Volume 491, Issue 1-2 , 2005 , Pages 190-196 ; 00406090 (ISSN) Sanjabi, S ; Sadrnezhaad, S. K ; Yates, K. A ; Barber, Z. H ; Sharif University of Technology
    2005
    Abstract
    The fabrication of TixNi1-x shape memory films using simultaneous magnetron sputtering from two separate, elemental targets was investigated. The films were deposited at room temperature and then annealed at 500 °C to achieve the shape memory effect. The influence of sputtering parameters such as power ratio to the targets (to control the composition) and Ar gas pressure (to control the film structure) were studied. It was found that the Ar gas pressure had a critical influence on the shape memory effect of the films. Characterization of the films was carried out by energy dispersive X-ray spectroscopy in a scanning electron microscope (to measure the film composition and uniformity), in... 

    Surface modification of exchange-coupled Co/NiO x magnetic bilayer by bias sputtering

    , Article Applied Surface Science ; Volume 252, Issue 2 , 2005 , Pages 466-473 ; 01694332 (ISSN) Sangpour, P ; Akhavan, O ; Moshfegh, A. Z ; Jafari, G. R ; Kavei, G ; Sharif University of Technology
    Elsevier  2005
    Abstract
    We have investigated the effect of bias voltage on sheet resistance, surface roughness and surface coverage of Co/NiO x magnetic bilayer. In addition, interface topography and corrosion resistance of the Ta/Co/Cu/Co/NiO x /Si(1 0 0) system have been studied for Co layers deposited at an optimum bias voltage. Atomic force microscopy (AFM) and four point probe sheet resistance (Rs) measurement have been used to determine surface and electrical properties of the sputtered Co layer at different bias voltages ranging from 0 to -80 V. The Co/NiO x bilayer exhibits a minimum surface roughness and low sheet resistance value with a maximum surface coverage at Vb=-60 V resulted in a slight increase of... 

    Influence of plasma sputtering treatment on natural dyeing and antibacterial activity of wool fabrics

    , Article Progress in Organic Coatings ; Volume 70, Issue 4 , 2011 , Pages 388-393 ; 03009440 (ISSN) Ghoranneviss, M ; Shahidi, S ; Anvari, A ; Motaghi, Z ; Wiener, J ; Šlamborová, I ; Sharif University of Technology
    2011
    Abstract
    In this paper, the effect of plasma sputtering treatment on the natural dyeing properties of wool and the possibility of substituting it for mordant treatment have been studied. We used madder and weld as natural dyes and copper sulfate (CuSO4) as a metal mordant. We also used, copper as the electrode material, in a DC magnetron plasma sputtering device. The color strength of samples was analyzed using a Reflective Spectrophotometer and washing and light fastnesses were investigated according to I.S.O. standard recommendations. The results show that, the color strength and fastness of dyed wool samples have been improved after plasma treatment. The antibacterial counting test was also used... 

    A high power high voltage short pulse width pulse generator using direct drive method in application of modulating-cathode tubes drive

    , Article IEEE International Symposium on Industrial Electronics, 5 July 2009 through 8 July 2009 ; 2009 , Pages 2097-2102 ; 9781424443499 (ISBN) Hasanzadeh, A ; Sadriyeh, S. M. R ; Mohammadi, A ; Maghsoudlou, B ; Mokhtari, H ; Alizadeh, H. R ; Shams Mousavi, S. M ; Sharif University of Technology
    Abstract
    The power supply of microwave tubes has high voltage and the possibility of produce high power pulse, which called in modulator. In this work, the results of design, construction and characterization of a direct drive pulse modulator for driving high power short pulse-width magnetron are reported. The sub-assemblies of modulator are; a primary high voltage supply, a switch bank with drivers and snubber circuits, a filament circuit, a digital control circuit with sensors and finally a pulse transformer. This paper is concerned with introduction and presentation of experimental evaluation of a new drive method for high power high voltage modulating-cathode microwave tubes. ©2009 IEEE  

    Magnetron-sputtered TixNy thin films applied on titanium-based alloys for biomedical applications: Composition-microstructure-property relationships

    , Article Surface and Coatings Technology ; Volume 349 , 2018 , Pages 251-259 ; 02578972 (ISSN) Nemati, A ; Saghafi, M ; Khamseh, S ; Alibakhshi, E ; Zarrintaj, P ; Saeb, M. R ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    Progress in tissue engineering and regenerative medicine necessitates the use of novel materials with promising bio-surface for biomedical applications. In this work, TixNy thin films are applied on biological TC4 substrates in a mixed atmosphere of Ar and N2 via magnetron sputtering system for the protection of TC4 alloy. The effects of N/Ti ratio on the phase structure, growth orientation, contact angle, and the mechanical and corrosion performances of thin films are discussed by implementation of composition-microstructure-property interrelationships. The phase structure of TixNy thin films is changed from amorphous-like to single phase Ti2N structure with increasing N/Ti ratio. In the...