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حرية الوصول المقاله
1 - Optical imaging and magnetic field simulation of a DC circular planar magnetron sputtering discharge
Ahmad Rastkar Ali Reza Niknam Mostafa SalahshoorIn this paper, the optical images of glow discharge plasma and the finite element method simulation of the magnetic field strength in a balanced and two types of unbalanced DC circular planar magnetron sputtering sources are presented. The investigation showed that wher أکثرIn this paper, the optical images of glow discharge plasma and the finite element method simulation of the magnetic field strength in a balanced and two types of unbalanced DC circular planar magnetron sputtering sources are presented. The investigation showed that wherever the magnetic field strength is stronger, the intensity of light and the ionization are greater and consequently, the deposition is higher. The comparison of recorded optical images with the finite element simulation results of the magnetic field strength indicated the correlation between regions of high magnetic field strength and high light emission. تفاصيل المقالة -
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2 - Role of substrate and deposition conditions on the texture evolution of titanium nitride thin film on bare and plasma-nitrided high-speed steel
Partha Saikia Alphonsa Joseph Ramakrishna Rane Bipul Kumar Saikia Subroto MukherjeeAbstractTitanium nitride (TiN) films are prepared by direct current (DC) magnetron sputtering of a titanium (Ti) target in an argon (Ar) + nitrogen (N2) atmosphere on bare and pulsed DC plasma-nitrided high-speed steel (AISI M2) substrate. One set of coating is deposite أکثرAbstractTitanium nitride (TiN) films are prepared by direct current (DC) magnetron sputtering of a titanium (Ti) target in an argon (Ar) + nitrogen (N2) atmosphere on bare and pulsed DC plasma-nitrided high-speed steel (AISI M2) substrate. One set of coating is deposited using different N2 partial pressures keeping the working pressure fixed, and it leads to variable film thickness. Another set of coating of equal thickness is prepared at the same working pressure with variable substrate biasing voltage. The detailed structure of the coatings is analyzed by X-ray diffraction study. The texture coefficient (Tc) determined from X-ray diffraction studies at various deposition conditions gives information about crystallographic orientation. It is found that the same deposition condition leads to different orientation of TiN coatings on bare AISI M2 and plasma-nitrided AISI M2 substrate. The results are discussed in terms of energy minimization and substrate-induced preferred orientation. تفاصيل المقالة -
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3 - Growth of europium-doped gallium oxide (Ga2O3:Eu) thin films deposited by homemade DC magnetron sputtering
Putut Marwoto Sugianto Sugianto Edy WibowoAbstractEuropium-doped gallium oxide (Ga2O3:Eu) thin films have successfully been grown using direct current magnetron sputtering by means of Eu concentration variation. Energy-dispersive X-ray spectroscopy spectra indicate gallium, oxygen, and europium elements as the أکثرAbstractEuropium-doped gallium oxide (Ga2O3:Eu) thin films have successfully been grown using direct current magnetron sputtering by means of Eu concentration variation. Energy-dispersive X-ray spectroscopy spectra indicate gallium, oxygen, and europium elements as the growing films' chemical compositions. Based on scanning electron microscopy images, the morphology of Ga2O3:Eu thin film is seemingly like a granulated nano-size configuration. In this study, UV-visible spectrophotometer results show that the variation of Eu doping concentration inflicted no change toward the optical bandgap of the growing films. The optical bandgaps of undoped Ga2O3 film and Ga2O3:Eu film were seen to be relatively similar, i.e., approximately 3.4 eV. Yet, the presence of Eu doping in Ga2O3 configuration had led to blueshift phenomenon when the concentration was 2% and redshift phenomenon when it was 5%. Photoluminescence emissions of all samples were observed in the red area with the emission peak between 593 and 602 nm. تفاصيل المقالة -
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4 - Optical characterization of Cu3N thin film with Swanepoel method
Davoud Dorranian Laya Dejam Gelareh MosayebianAbstractSwanepoel method is employed for spectroscopic determination of optical properties of Cu3N thin film using transmittance data. Investigated films have been deposited using reactive magnetron sputtering system. Deposition time was 9 to 21 min. Refractive index, a أکثرAbstractSwanepoel method is employed for spectroscopic determination of optical properties of Cu3N thin film using transmittance data. Investigated films have been deposited using reactive magnetron sputtering system. Deposition time was 9 to 21 min. Refractive index, absorption coefficient, and bandgap energy of the samples are determined. Thickness of the films is calculated by Swanepoel method, and result is compared with the thickness of the films measured by profilmeter. It is shown that Swanepoel method is a reliable way to calculate the optical constants of thin films when the transmittance spectrum of the film is influenced by wavelike patterns due to reflection of the probe beam from different interfaces. تفاصيل المقالة -
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5 - Effects of various deposition times and RF powers on CdTe thin film growth using magnetron sputtering
Z. Ghorannevis E. Akbarnejad M. GhorannevissAbstractCadmium telluride (CdTe) is a p-type II-VI compound semiconductor, which is an active component for producing photovoltaic solar cells in the form of thin films, due to its desirable physical properties. In this study, CdTe film was deposited using the radio fre أکثرAbstractCadmium telluride (CdTe) is a p-type II-VI compound semiconductor, which is an active component for producing photovoltaic solar cells in the form of thin films, due to its desirable physical properties. In this study, CdTe film was deposited using the radio frequency (RF) magnetron sputtering system onto a glass substrate. To improve the properties of the CdTe film, effects of two experimental parameters of deposition time and RF power were investigated on the physical properties of the CdTe films. X-ray Diffraction (XRD), atomic force microscopy (AFM) and spectrophotometer were used to study the structural, morphological and optical properties of the CdTe samples grown at different experimental conditions, respectively. Our results suggest that film properties strongly depend on the experimental parameters and by optimizing these parameters, it is possible to tune the desired structural, morphological and optical properties. From XRD data, it is found that increasing the deposition time and RF power leads to increasing the crystallinity as well as the crystal sizes of the grown film, and all the films represent zinc blende cubic structure. Roughness values given from AFM images suggest increasing the roughness of the CdTe films by increasing the RF power and deposition times. Finally, optical investigations reveal increasing the film band gaps by increasing the RF power and the deposition time. تفاصيل المقالة -
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6 - Role of Ar/O2 mixture on structural, compositional and optical properties of thin copper oxide films deposited by DC magnetron sputtering
N. Aghilizadeh A. H. Sari D. DorranianAbstractIn this study, the effect of oxygen content on a thin copper oxide layer deposited on BK7 and steel substrates by DC magnetron sputtering were investigated. Argon as working gas with impurity of 99.9% and various oxygen ratios were used to sputter a pure Cu cath أکثرAbstractIn this study, the effect of oxygen content on a thin copper oxide layer deposited on BK7 and steel substrates by DC magnetron sputtering were investigated. Argon as working gas with impurity of 99.9% and various oxygen ratios were used to sputter a pure Cu cathode target in a cylindrical geometry. The produced samples were analyzed by X-ray diffraction (XRD), energy-dispersive X-ray (EDX), atomic force microscopy (AFM), and spectrophotometry techniques. The films thickness was measured by profilometer facility. The results show that by increasing oxygen content in the working gas the sputtering rate reduces. Moreover, the type of oxide phase (Cu2O or CuO) in the synthesized layer and consequently its optical properties dramatically depend on Ar/O2 ratio in the working gas. تفاصيل المقالة -
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7 - Structural and morphological properties of ITO thin films grown by magnetron sputtering
Z. Ghorannevis E. Akbarnejad M. GhorannevissAbstractPhysical properties of transparent and conducting indium tin oxide (ITO) thin films grown by radiofrequency (RF) magnetron sputtering are studied systematically by changing deposition time. The X-ray diffraction (XRD) data indicate polycrystalline thin films wit أکثرAbstractPhysical properties of transparent and conducting indium tin oxide (ITO) thin films grown by radiofrequency (RF) magnetron sputtering are studied systematically by changing deposition time. The X-ray diffraction (XRD) data indicate polycrystalline thin films with grain orientations predominantly along the (2 2 2) and (4 0 0) directions. From atomic force microscopy (AFM) it is found that by increasing the deposition time, the roughness of the film increases. Scanning electron microscopy (SEM) images show a network of a high-porosity interconnected nanoparticles, which approximately have a pore size ranging between 20 and 30 nm. Optical measurements suggest an average transmission of 80 % for the ITO films. Sheet resistances are investigated using four-point probes, which imply that by increasing the film thickness the resistivities of the films decrease to 2.43 × 10−5 Ω cm. تفاصيل المقالة -
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8 - Influence of O2 and N2 Concentrations on the Characteristics of Plasma in DC Cylindrical Magnetron Discharge by Langmuir Probe
Kiomars Yasserian Zahra KarimiUsing the Langmuir probe method, the reactive plasma parameters were studied in different ratios of oxygen and nitrogen concentrations in a DC cylindrical discharge device.The plasma parameters such as plasma potential, electron density and electron temperature weree أکثرUsing the Langmuir probe method, the reactive plasma parameters were studied in different ratios of oxygen and nitrogen concentrations in a DC cylindrical discharge device.The plasma parameters such as plasma potential, electron density and electron temperature wereextracted from the current-voltage characteristic’s curve of Langmuir probe to find the optimum conditions for deposit the oxynitride thin films.Chromium thin films were exposed to various O2/N2 partial pressures to obtain optimum valuefor produce of oxynitride chrome thin films. In addition, the influence of the magnetic field on the structural properties of the chrome oxynitride thin films was obtained. It is observed that for equal percentage of reactive gases, the optimum condition of the plasma discharge takes place in which the crystalline phases of oxynitride chrome thin films appear. تفاصيل المقالة -
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9 - Formation of Cupric Oxide Films on Quartz Substrates by Annealing the Copper Films
Alireza Hojabri Fatemeh Hajakbari Masoumeh NajarsadeghiIn the present work, cupric oxide (CuO) films were obtained through thermal annealing of the copper (Cu) films deposited on quartz substrates by DC magnetron sputtering method. The annealing was performed in air atmosphere for different times ranging from 60-240 min أکثرIn the present work, cupric oxide (CuO) films were obtained through thermal annealing of the copper (Cu) films deposited on quartz substrates by DC magnetron sputtering method. The annealing was performed in air atmosphere for different times ranging from 60-240 min at temperature of 400 ºC. The influence of annealing times on structural and morphological properties of the films was investigated by different analyses. The XRD results showed that the as-deposited film was Cu, while those annealed at different times were composed of CuO. By increasing annealing times up to 180 min, the intensity of CuO diffraction peaks increased and further enhancement of annealing times led to decrease of the crystallinity. Also, the AFM images of the films conformed the dependence of surface morphology to annealing times. تفاصيل المقالة -
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10 - Fabricating the Tribological Properties and Investigating of Ni3Al-MoS2 Composite Coating
Mahdi Mirzaaghaei Mohammad-Hossein Enayati Mahdi AhmadiSelf-lubricant coatings are among the newly improved type of coatings to reduce the coefficient of friction and protect the substrate in various conditions. Magnetron sputtering is the best technology to fabricate coatings with good morphology. In this paper, the tribol أکثرSelf-lubricant coatings are among the newly improved type of coatings to reduce the coefficient of friction and protect the substrate in various conditions. Magnetron sputtering is the best technology to fabricate coatings with good morphology. In this paper, the tribological properties of magnetron sputtered Ni3Al-MoS2 coating on 4340 steel are reported. For this purpose, five tablets of Ni3Al-30 wt.% MoS2 were prepared as the target material and were placed in a copper holder. At last, we have sputtered from the target using the best sputtering condition to get a good morphology and microstructure of the coating. The morphology and microstructure of the coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The tribological properties of Ni3Al-MoS2 coating were investigated using a ball-on-disc tribometer at atmospheric conditions at room temperature. SEM was used to examine the morphology of the wear track after the ball-on-disc test. The Ni3Al-MoS2 composite coating showed lower frictions coefficient and higher wear resistance because of the hard Ni3Al matrix and soft MoS2 particles. تفاصيل المقالة -
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11 - اثر افزودن سیلیسیم بر رفتار مکانیکی و خوردگی پوشش کاربید تانتالم تولید شده به روش کندوپاش مگنترونی
علیرضا حسینی میناسادات امامیان مصطفی علیشاهیدر این پژوهش پوششهای Ta، TaC و TaSiC به روش کندوپاش مگنترونی غیرواکنشی لایهنشانی شده و خواص ساختاری، ریزساختاری، مکانیکی و خوردگی بررسی شده است. نتایج XRD نشان دادند که پوشش Ta ساختار کریستالی تانتالم α، پوشش TaC ساختار کریستالی TaC0.6 و پوشش TaSiC ماهیت شبهآمو أکثردر این پژوهش پوششهای Ta، TaC و TaSiC به روش کندوپاش مگنترونی غیرواکنشی لایهنشانی شده و خواص ساختاری، ریزساختاری، مکانیکی و خوردگی بررسی شده است. نتایج XRD نشان دادند که پوشش Ta ساختار کریستالی تانتالم α، پوشش TaC ساختار کریستالی TaC0.6 و پوشش TaSiC ماهیت شبهآمورف از خود نشان دادند. در این ارتباط، پوشش Ta ریزساختاری ستونی با زبری بالا و تنش پسماند کششی از خود نشان داد، در حالیکه افزودن کربن و سیلیسیم به پوشش سبب فشردهشدن ریزساختار، کاهش زبری سطح و تغییر ماهیت تنش پسماند از کششی به فشاری شد. همچنین نتایج آزمون نانوفرورونده نشان داد که افزودن کربن به پوشش تانتالم باعث افزایش حدود چهار برابری سختی پوشش میشود، ولی افزودن سیلیسیم به پوشش TaC سختی پوشش را اندکی کاهش میدهد. مطالعات خوردگی نشان داد همه پوششها نسبت به زیرلایه ST37 ماهیتی کاتدی از خود نشان دادند که میتواند منجر به خوردگی گالوانیک شود. علاوه بر این نتایج خوردگی نشان داد که پوشش Ta بازده حفاظتی به میزان ٪9/78 برای فولاد ساده کربنی را به همراه دارد و افزودن کربن و سیلیسیم به پوشش سبب افزایش بازده حفاظتی به مقادیر ٪1/90 و ٪5/95 به ترتیب برای پوششهای TaC و TaSiC میشود .در این ارتباط نقش این عناصر در فشردگی پوشش و کاهش مسیرهایی که محلول خورنده میتواند به زیرلایه برسد، کلیدی تشخیص داده شد. تفاصيل المقالة -
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12 - بررسی رفتار خوردگی پوشش تانتالم لایهنشانی شده به روش کندوپاش مگنترونی
مصطفی علیشاهی فرزاد محبوبی سیدمحمد موسوی خوئیدر این پژوهش پوشش تانتالم به روش کندوپاش مگنترونی جریان مستقیم روی سیلیکون (۱۰۰) و فولاد زنگنزن L۳۱۶ لایهنشانی شد. خواص ساختاری پوشش تانتالم به کمک آزمون پراش پرتو ایکس ارزیابی شده و از میکروسکوپهای الکترونی عبوری و روبشی و همچنین میکروسکوپ نیروی اتمی جهت بررسی سطح م أکثردر این پژوهش پوشش تانتالم به روش کندوپاش مگنترونی جریان مستقیم روی سیلیکون (۱۰۰) و فولاد زنگنزن L۳۱۶ لایهنشانی شد. خواص ساختاری پوشش تانتالم به کمک آزمون پراش پرتو ایکس ارزیابی شده و از میکروسکوپهای الکترونی عبوری و روبشی و همچنین میکروسکوپ نیروی اتمی جهت بررسی سطح مقطع و مورفولوژی سطح پوشش استفاده شد. افزون بر این، رفتار خوردگی پوشش تانتالم در مقایسه با فولاد زنگنزن L۳۱۶ به کمک آزمون پلاریزاسیون پتانسیودینامیک بررسی شده و از آزمون طیفسنجی امپدانس الکتروشیمیایی جهت تعیین مکانیزمهای خوردگی استفاده شد. نتایج نشان دادند که استفاده از لایه آستری نیترید تانتالم، میتواند سبب تغییر ساختار کریستالی پوشش تانتالم از مخلوط فازی α و β به ساختار تک فاز α، و کاهش مقاومت الکتریکی پوشش از حدود ۹۰ به ۱۵ میکرواهم در سانتیمتر شود. همچنین مطالعات میکروسکوپی نشان دادند که پوشش تانتالم ساختاری ستونی و بسیار فشرده با سطحی یکنواخت و بدون عیب از خود نشان داده و زبری میانگین آن کمتر از ۶ نانومتر اندازهگیری شد. نتایج آزمونهای خوردگی نشان داد که پوشش تانتالم مانند یک سد فیزیکی از تماس محلول خورنده با زیرلایه جلوگیری کرده و بازده حفاظت بیشتر از ۷۰ درصد از سبب میشود. در این ارتباط، نفوذ محلول خورنده به زیرلایه از طریق حفرات راهباز موجود در پوشش به عنوان مکانیزم خوردگی پوشش تانتالم شناخته شد و شاخص تخلخل پوشش حدود ۶ درصد تعیین شد. تفاصيل المقالة -
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13 - بررسی چقرمگی شکست و حساسیت به نرخ کرنش لایه نازک نیترید تانتالوم تولید شده به روش کندوپاش مغناطیسی واکنشی
Siavash فیروزآبادی کامران دهقانی مالک نادری فرزاد محبوبینیترید تانتالوم به دلیل سختی بالا و مقاومت به خوردگی خوب توانسته است توجهات زیادی را به عنوان پوششی مناسب جلب نماید. اما چقرمگی شکست لایههای نازک نیترید تانتالوم که یکی از عوامل تاثیرگذار بر طول عمر پوشش است، هنوز به خوبی بررسی نشده است. در این پژوهش، برای نخستین بار، أکثرنیترید تانتالوم به دلیل سختی بالا و مقاومت به خوردگی خوب توانسته است توجهات زیادی را به عنوان پوششی مناسب جلب نماید. اما چقرمگی شکست لایههای نازک نیترید تانتالوم که یکی از عوامل تاثیرگذار بر طول عمر پوشش است، هنوز به خوبی بررسی نشده است. در این پژوهش، برای نخستین بار، چقرمگی شکست، پلاستیسیته و حساسیت به نرخ کرنش لایه های نازک نیترید تانتالوم به کمک روش نانو فرورونده بررسی و ارزیابی شد. در این بررسی نشان داده شده که تغییرات چقرمگی شکست فازهای مختلف نیترید تانتالوم از MPa√m 6/0 تا MPa√m 7/8 بسته به میزان نیتروزن موجود در سیستم لایه نشانی و به تبع آن نیتروژن موجود در شبکه نیترید تانتالوم افزایش مییابد. همچنین دو فاز مهم نیترید تانتالوم یعنی γ-Ta2N و δ-TaN دارای حساسیت به نرخ کرنش منفی و مثبت هستند که میتوان این رفتار را به تغییرات ساختار فازی حین انجام آزمون نسبت داد. تفاصيل المقالة
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