Hypereutectic Al-Si-Cu coatings were prepared by supersonic atmospheric plasma spraying to enhance the surface performance of lightweight alloys.To find out optimum process conditions and achieve desirable coatings,th...Hypereutectic Al-Si-Cu coatings were prepared by supersonic atmospheric plasma spraying to enhance the surface performance of lightweight alloys.To find out optimum process conditions and achieve desirable coatings,this work focuses on the influence of three important parameters(in-flight particle temperature,impact velocity,and substrate temperature)on the collected splats morphology coatings microstructure and microhardness.Results show that appropriate combinations of temperature and velocity of in-flight particles cannot only completely melt hypereutectic Al-Si-Cu particles especially the primary Si phase,but also provide the particles with sufficient kinetic energy.Thus,the optimized coating consists of 98.6%of fully-melted region with nanosized coupled eutectic and 0.9%of porosity.Increasing the substrate deposition temperature promotes the transition from inhomogeneous banded microstructure to homogeneous equiaxed microstructure with a lower porosity level.The observations are further interpreted by a newly developed phase-change heat transfer model on quantitatively revealing the solidification and remelting behaviors of several splats deposited on substrate Besides,phase evolutions including the formation of supersaturatedα-Al matrix solid solution,growth of Si and Al_(2)Cu phases at different process conditions are elaborated.An ideal microstructure(low fractions of unmelted/partially-melted regions and defects)together with solid solution,grain refinement and second phase strengthening effects contributes to the enhanced microhardness of coating.This integrated study not only provides a framework for optimizing Al-Si based coatings via thermal spraying but also gives valuable insights into the formation mechanisms of this class of coating materials.展开更多
Hydrogenated microcrystalline silicon (μcSi:H) thin films were deposited by an radio frequency (RF)(13.56 MHz) magnetron sputtering at different substrate temperatures (100–300℃), and the influences of substrate te...Hydrogenated microcrystalline silicon (μcSi:H) thin films were deposited by an radio frequency (RF)(13.56 MHz) magnetron sputtering at different substrate temperatures (100–300℃), and the influences of substrate temperature on the growth and properties ofμc-Si:H thin films were investigated. Surface roughness and crystallinity of the thin films increase as substrate temperature increases. And all thin films are at the transition region(X_(c)=49.2%~61.0%). Theμc-Si:H thin films deposited at lower substrate temperature (≤200℃) represent a weak(220) preferred orientation, while the thin films deposited at higher substrate temperature (≥250℃) exhibit a weak(111) preferred orientation. The μc-Si:H thin films have a dense structure, and the structural compactness of the thin films slightly increases with substrate temperature increasing. The Fourier transform infrared spectroscopy (FTIR) results indicate that theμc-Si:H thin films have a low hydrogen content (3.9 at%–5.6 at%), which is in favor of reducing light-induced degradation effect.展开更多
A series of TbDyFe films were prepared by DC magnetron sputtering. The effects of substrate temperature and annealing temperature on the phase structure and the magnetic properties of the sample films were investigate...A series of TbDyFe films were prepared by DC magnetron sputtering. The effects of substrate temperature and annealing temperature on the phase structure and the magnetic properties of the sample films were investigated. The an-nealing treatment has a significant influence on the microstructure and the magnetic properties of the sample. The results obtained by XRD indicate that the films deposited at a temperature lower than 525℃ are amorphous and have an easy magnetization direction perpendicular to the film plane. An RFe2 phase is formed in the sample annealed at 550℃ and the residual phases observed are Fe and rare earth oxide. The magnetic properties Hc and Mr/Ms of the film annealed at 550℃ obtain the maximum values,for which the formation of the RFe2 phase is mainly responsible. An annealing treatment leads to a rotation of the sample’s easy axis from being parallel to the film surface to becoming vertical.展开更多
The NiO-Cu composite films were deposited on a glass substrate at various substrate temperatures by DC reactive magnetron sputtering technique. The effect of substrate temperature on the structural, optical, morpholog...The NiO-Cu composite films were deposited on a glass substrate at various substrate temperatures by DC reactive magnetron sputtering technique. The effect of substrate temperature on the structural, optical, morphological and electrical properties of the films was mainly investigated. X-ray diffraction studies revealed that when the substrate temperature increased to above 200 ℃, the preferred orientation tended to move to another preferred site from （220） to （111） and had a band gap values increased with increasing substrate observed that the grain size and root mean square stable cubic structure. The optical transmittance and temperature. From the morphological studies, it was roughness were increased with increasing substrate temperature. The electrical resistivity of the film decreased to 0.017 Ωcm at high substrate temperature of 400 ℃.展开更多
Transparent conducting molybdenum-doped zinc oxide （MZO） films were successfully prepared by radio frequency （RF） magnetron sputtering method on glass substrates under different substrate temperatures. The nature ...Transparent conducting molybdenum-doped zinc oxide （MZO） films were successfully prepared by radio frequency （RF） magnetron sputtering method on glass substrates under different substrate temperatures. The nature of MZO film is polycrystalline with hexagonal structure and a preferred orientation along c-axis. With increasing substrate temperature from room temperature to 400℃, the crystallinity of the films is deteriorated and the resistivity increases sharply due to both the decrease of carrier concentration and Hall mobility. The lowest resistivity achieved is 9.2×10^-4 Ω· cm with a high Hall mobility of 30 cm^2·V^-1·s^-1 for the film deposited at room temperature. The average transmttance in the visible range exceeds 85% for all the samples. The optical band gap decreases from 3.30 to 3.25 eV with substrate temperature from room temperature to 400℃.展开更多
Pd-capped Mg78Y22 thin films have been prepared by direct current magnetron co-sputtering system at different substrate temperatures and their electrochemical hydrogen storage properties have been investigated.It is f...Pd-capped Mg78Y22 thin films have been prepared by direct current magnetron co-sputtering system at different substrate temperatures and their electrochemical hydrogen storage properties have been investigated.It is found that rising substrate temperature to 60 ℃ can coarsen the surface of thin film,thus facilitating the diffusion of hydrogen atoms and then enhancing its discharge capacity to 1725 mAh·g-1.Simultaneously,the cyclic stability is effectively improved due to the increased adhesion force between film and substrate as a function of temperature.In addition,the specimen exhibits a very long and flat discharge plateau at about —0.67 V,at which nearly 60%of capacity is maintained.The property is favorable for the application in metal hydride/nickel secondary batteries.The results indicate that rising optimal substrate temperature has a beneficial effect on the electrochemical hydrogen storage of Mg-Y thin films.展开更多
The 2D kinetic Monte Carlo （KMC） simulation was used to study the effects of different substrate temperatures on the microstructure of Ni-Cr films in the process of deposition by the electron beam physical vapor dep...The 2D kinetic Monte Carlo （KMC） simulation was used to study the effects of different substrate temperatures on the microstructure of Ni-Cr films in the process of deposition by the electron beam physical vapor deposition （EB-PVD）. In the KMC model, substrate was assumed to be a ＂surface＂ of tight-packed rows, and the simulation includes two phenomena： adatom-surface collision and adatom diffusion. While the interaction between atoms was described by the embedded atom method, the jumping energy was calculated by the molecular static （MS） calculation. The initial location of the adatom was defined by the Momentum Scheme. The results reveal that there exists a critical substrate temperature which means that the lowest packing density and the highest surface roughness structure will be achieved when the temperature is lower than the smaller critical value, while the roughness of both surfaces and the void contents keep decreasing with the substrate temperature increasing until it reaches the higher critical value. The results also indicate that the critical substrate temperature rises as the deposition rate increases.展开更多
The contacting interface between the substrate and water-cooled base is vital to the substrate temperature during diamond films deposition by a DC （direct current） plasma jet. The effects of the solid contacting are...The contacting interface between the substrate and water-cooled base is vital to the substrate temperature during diamond films deposition by a DC （direct current） plasma jet. The effects of the solid contacting area,conductive materials and fixing between the substrate and the base were investigated without affecting the other parameters. Experimental results indicated that the preferable solid contacting area was more than 60% of total contacting areal; the particular Sn-Pb alloy was more suitable for conducting heat and the concentric fixing ring was a better setting for controlling the substrate temperature. The result was explained in terms of the variable thermal contact resistance at the interface between substrate and base. The diamond films were analyzed by scanning electron microscopy （SEM） for morphology, X-ray diffraction （XRD） for the intensity of characteristic spectroscopy and Raman spectroscopy for structure.展开更多
Permalloy Ni80Fe20 films have been grown on thermal oxidized Si (111) wafers by magnetron sputtering at well-controlled substrate temperatures of 300, 500, 640 and 780 K in 0.65 Pa argon pressure. The base pressure wa...Permalloy Ni80Fe20 films have been grown on thermal oxidized Si (111) wafers by magnetron sputtering at well-controlled substrate temperatures of 300, 500, 640 and 780 K in 0.65 Pa argon pressure. The base pressure was about 1×10-4 Pa. The deposition rate was about 5 nm/min for all the films. The structure of the films was studied using X-ray diffraction, scanning electron microscopy and atomic force microscopy. The composition of the films was analyzed using scanning Auger microprobe. The resistance and magnetoresistance of the films were measured using four-point probe technique. The results show that the content of oxygen in the films decreases gradually with raising substrate temperature. In addition, the surface morphology of the films presents notable change with the increasing of the substrate temperature; the residual gases and defects decrease and the grains have coalesced evidently, and then the grains have grown up obviously and the texture of (111) orientation develops gradually in the growing film. As a result, the resistivity reduces apparently and magnetoresistance ratio increases markedly with raising substrate temperature.展开更多
TiO2-CeO2 films were deposited on soda-lime glass substrates at varied substrate temperatures by rf magnetron sputtering using 40% molar TiO2-60% molar CeO2 ceramic target in Ar：O2=95：5 atmosphere.The structure,surf...TiO2-CeO2 films were deposited on soda-lime glass substrates at varied substrate temperatures by rf magnetron sputtering using 40% molar TiO2-60% molar CeO2 ceramic target in Ar：O2=95：5 atmosphere.The structure,surface composition,UV-visible spectra of the films were measured by scanning electron microscopy and X-ray diffraction,and X-ray photoelectron spectroscopy,respectively.The experimental results show that the films are amorphous,there are only Ti^4＋ and Ce^4＋ on the surface of the films,the obtained TiO2-CeO2 films shou a good uniformity and high densification,and the films deposited on the glass can shield ultraviolet light without significant absorpition of visible light,the films deposited on substrates at room temperature and 220℃ absorb UV effectively.展开更多
Ta-doped titanium dioxide films are deposited on fused quartz substrates using the rf magnetron sputtering technique at different substrate temperatures. After post-annealing at 550℃ in a vacuum, all the films are cr...Ta-doped titanium dioxide films are deposited on fused quartz substrates using the rf magnetron sputtering technique at different substrate temperatures. After post-annealing at 550℃ in a vacuum, all the films are crystallized into the polycrystalline anatase TiO2 structure. The effects of substrate temperature from room temperature up to 350℃ on the structure, morphology, and photoelectric properties of Ta-doped titanium dioxide films are analyzed. The average transmittance in the visible region（400-800 nm） of all films is more than 73%.The resistivity decreases firstly and then increases moderately with the increasing substrate temperature. The polycrystalline film deposited at 150℃ exhibits a lowest resistivity of 7.7 × 10^-4Ω·cm with the highest carrier density of 1.1×10^21 cm^-3 and the Hall mobility of 7.4 cm^2·V^-1s^-1.展开更多
The effects of the substrate temperature on the deposition and microstructure of the 304 stainless steel （SS） cold gas dynamic spraying （CGDS） coatings were investigated. It was found that the higher substrate tem...The effects of the substrate temperature on the deposition and microstructure of the 304 stainless steel （SS） cold gas dynamic spraying （CGDS） coatings were investigated. It was found that the higher substrate temperature could increase the deposition rate of the 304 SS particles,even the oxide films existed at the interface. There was a critical oxide film with a thickness of 3 -4 um which could be destroyed by the impacted particles. The micro-hardness and microstructure of the 304 SS coatings under different substrate preheating temperatures were almost the same.展开更多
Transparent TiO2/TiN/TiO2 multi-layer solar control coatings were prepared on normal soda-lime-silica float glass substrate by using d.c. reactive magnetron sputtering at substrate temperature ranging from room temper...Transparent TiO2/TiN/TiO2 multi-layer solar control coatings were prepared on normal soda-lime-silica float glass substrate by using d.c. reactive magnetron sputtering at substrate temperature ranging from room temperature to 620℃ . The dependence of optical properties of the coatings and the coating composition, on the substrate temperature was studied. The results of the optical properties show that as the substrate temperature increases, a visible transmittance as high as 65% can be obtained. When the substrate temperature is higher than 370℃ , the infrared reflectance decreases. The results of X-ray photoelectron spectroscopy (XPS) show that when the substrate temperature is higher than 520℃ in oxygen atmosphere, the formation of thin surface over-layers (TiNxOy,) on top of the TiN films can be observed. When the substrate temperature is at 62℃ , the oxynitride become TiO2, which results in the optical degradation of TiN layer in infrared reflectance.展开更多
Polycrystalline silicon （poly-Si） films were deposited using Ar diluted SiH4 gaseous mixture by electron cyclotron resonance plasma-enhanced chemical vapor deposition （ECR-PECVD）. The effects of the substrate temp...Polycrystalline silicon （poly-Si） films were deposited using Ar diluted SiH4 gaseous mixture by electron cyclotron resonance plasma-enhanced chemical vapor deposition （ECR-PECVD）. The effects of the substrate temperature on deposition rate, crystallinity, grain size and the configuration of H existing in poly-Si film were investigated. The results show that, comparing with H2 dilution, Ar dilution could significantly decrease the concentration of H on the growing surface. When the substrate temperature increased, the deposition rate increased and the concentration of H decreased monotonously, but the crystallinity and the grain size of poly-Si films exhibited sophisticated trends. It is proposed that the crystallinity of the films is determined by a competing balance of the self-diffusion activity of Si atoms and the deposition rate. At substrate temperature of 200℃, the deposited film exhibits the maximum poly-Si volume fraction of 79%. Based on these results, higher substrate temperature is suggested to prepare the poly-Si films with advanced stability and compromised crystallinity at high deposition rate.展开更多
MgO thin films were deposited on Si（100） substrates by laser ablation under various substrate temperatures （Tsub）,expecting to provide a candidate buffer layer for the textured growth of functional perovskite oxid...MgO thin films were deposited on Si（100） substrates by laser ablation under various substrate temperatures （Tsub）,expecting to provide a candidate buffer layer for the textured growth of functional perovskite oxide films on Si substrates.The effect of Tsub on the preferred orientation,crystallinity and surface morphology of the films was investigated.MgO films in single-phase were obtained at 473-973 K.With increasing Tsub,the preferred orientation of the films changed from （200） to （111）.The crystallinity and surface morphology was different too,depending on Tsub.At Tsub=673 K,the MgO film became uniform and smooth,exhibiting high crystallinity and a dense texture.展开更多
This paper presents the substrate temperature dependence of opto-electrical properties for transparent conducting Al-doped ZnO films prepared on polyisocyanate (PI) substrates by r f sputtering. Polycrystalline ZnO:Al...This paper presents the substrate temperature dependence of opto-electrical properties for transparent conducting Al-doped ZnO films prepared on polyisocyanate (PI) substrates by r f sputtering. Polycrystalline ZnO:Al films with good adherence to the substrates having a (002) preferred orientation have been obtained with resistivities in the range from 4.1×10-3to 5.3×104 Ωcm, carrier densities more than 2.6×1020 cm-3 and Hall mobilities between 5.78 and 13.11 cm2/V/s for films. The average transmittance reaches 75% in the visible spectrum. The quality of obtained films depends on substrate temperature during film fabrication.展开更多
Superconducting thin films of YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-x</sub>（Y-Ba-Cu-O） with Tc more than 85K have been deposited in situ by metalorganic chemical vapor deposition ...Superconducting thin films of YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-x</sub>（Y-Ba-Cu-O） with Tc more than 85K have been deposited in situ by metalorganic chemical vapor deposition （MOCVD） on yttria stabilized zirconia（YSZ） substrates. The relationship of film orientation on substrate temperature and the lowest formation temperature region of superconducting phase have been obtained after changing the substrate temperature. The epitaxial relation between Y-Ba-Cu-O films and the YSZ su bstrates were discussed.展开更多
To explore the relationship between the chemical bonding and mechanical properties for germanium carbide (Ge1-xCx) films,the Ge1-xCx films are prepared via reactive magnetron sputtering in a mixture of CH4/Ar discharg...To explore the relationship between the chemical bonding and mechanical properties for germanium carbide (Ge1-xCx) films,the Ge1-xCx films are prepared via reactive magnetron sputtering in a mixture of CH4/Ar discharge,and their composition,chemical bonding and hardness were investigated as a function of substrate temperature (Ts). The results show that Ts remarkably influences the chemical bonding of Ge1-xCx film,which results in a pronounced change in the film hardness. As Ts increases from ambient (60 ℃) to 500 ℃,the Ge content in the film gradually increases,which promotes forming sp3 C-Ge bonds in the film at the expense of sp2C-C bonds. Furthermore,it is found that with increasing Ts the fraction of C-H bonds in Ge1-xCx film gradually decreases,which is attributed to an enhancement in the desorption rate of C-Hn(n=1,2,3) species decomposed from methane. The transition from graphite-like sp2 C-C to diamond-like sp3C-Ge bonds as well as the reduction in C-H bonds in the film with increasing Ts promotes forming the compact three-dimensional network structure,which significantly enhances the hardness of the film from 5.8 to 10.1 GPa.展开更多
Amorphous hydrogenated carbon thin films have been deposited with benzene plasma in an electron cyclotron resonance (ECR) plasma enhanced chemical vapor deposition system. The characteristic of Benzene discharge plas...Amorphous hydrogenated carbon thin films have been deposited with benzene plasma in an electron cyclotron resonance (ECR) plasma enhanced chemical vapor deposition system. The characteristic of Benzene discharge plasma has been monitored by Mast spectrometry. It shows that the majority of the plasma species in the downstream ECR Plasma with benzene as gas source are acetylene, ethylene and higher mass species. In the experiments, the effects of the substrate temperature on the deposition rates have been emphatically studied. The structures of the films were analyzed by FTIR and Ramam spectrum.The results show that when the substrate temperature rises, the deposition rate drops down, the hydrogen Foment decreases, with the higher SP3 content being presented in the film.展开更多
Due to their particular optical characteristics,metallic island films have the potential to significantly increase the energy conversion efficiency of solar cell.We experimentally and theoretically investigated the ef...Due to their particular optical characteristics,metallic island films have the potential to significantly increase the energy conversion efficiency of solar cell.We experimentally and theoretically investigated the effect of substrate temperature on the morphologies and optical properties of the silver island films.At low temperature,below 300 ℃,as the substrate temperature increases.Compared to the films prepared at room temperature,the sizes of nanoparticles decrease and the Absorption peaks shift to shorter wavelength accompanied by an increase density resulting in a 150% Absorption efficiency.As the substrate temperature goes up to 300 ℃,nanoparticles with larger in-plan(X-Y)dimensions are formed,the number density decreases and the Absorption peaks redshift but the Absorption efficiency is still 10% higher.Numerical simulation reveals that these behaviors are a consequence of morphologies transformation.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51535011,51675531,52075542 and 52075543)the Pre-Research Program in National 13th FiveYear Plan(No.61409230603)+2 种基金the Joint Fund of Ministry of Education for Pre-research of Equipment(No.6141A02033120)the China Postdoctoral Science Foundation(No.2019M653598)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2020JQ-911)。
文摘Hypereutectic Al-Si-Cu coatings were prepared by supersonic atmospheric plasma spraying to enhance the surface performance of lightweight alloys.To find out optimum process conditions and achieve desirable coatings,this work focuses on the influence of three important parameters(in-flight particle temperature,impact velocity,and substrate temperature)on the collected splats morphology coatings microstructure and microhardness.Results show that appropriate combinations of temperature and velocity of in-flight particles cannot only completely melt hypereutectic Al-Si-Cu particles especially the primary Si phase,but also provide the particles with sufficient kinetic energy.Thus,the optimized coating consists of 98.6%of fully-melted region with nanosized coupled eutectic and 0.9%of porosity.Increasing the substrate deposition temperature promotes the transition from inhomogeneous banded microstructure to homogeneous equiaxed microstructure with a lower porosity level.The observations are further interpreted by a newly developed phase-change heat transfer model on quantitatively revealing the solidification and remelting behaviors of several splats deposited on substrate Besides,phase evolutions including the formation of supersaturatedα-Al matrix solid solution,growth of Si and Al_(2)Cu phases at different process conditions are elaborated.An ideal microstructure(low fractions of unmelted/partially-melted regions and defects)together with solid solution,grain refinement and second phase strengthening effects contributes to the enhanced microhardness of coating.This integrated study not only provides a framework for optimizing Al-Si based coatings via thermal spraying but also gives valuable insights into the formation mechanisms of this class of coating materials.
基金financially supported by the Young Scientists Fund of the National Natural Science Foundation of China (No. 61106096)the Natural Science Foundation of Ningbo, China (No. 2012A610120)。
文摘Hydrogenated microcrystalline silicon (μcSi:H) thin films were deposited by an radio frequency (RF)(13.56 MHz) magnetron sputtering at different substrate temperatures (100–300℃), and the influences of substrate temperature on the growth and properties ofμc-Si:H thin films were investigated. Surface roughness and crystallinity of the thin films increase as substrate temperature increases. And all thin films are at the transition region(X_(c)=49.2%~61.0%). Theμc-Si:H thin films deposited at lower substrate temperature (≤200℃) represent a weak(220) preferred orientation, while the thin films deposited at higher substrate temperature (≥250℃) exhibit a weak(111) preferred orientation. The μc-Si:H thin films have a dense structure, and the structural compactness of the thin films slightly increases with substrate temperature increasing. The Fourier transform infrared spectroscopy (FTIR) results indicate that theμc-Si:H thin films have a low hydrogen content (3.9 at%–5.6 at%), which is in favor of reducing light-induced degradation effect.
基金the National Natural Science Foundation of China (No. 50271017).
文摘A series of TbDyFe films were prepared by DC magnetron sputtering. The effects of substrate temperature and annealing temperature on the phase structure and the magnetic properties of the sample films were investigated. The an-nealing treatment has a significant influence on the microstructure and the magnetic properties of the sample. The results obtained by XRD indicate that the films deposited at a temperature lower than 525℃ are amorphous and have an easy magnetization direction perpendicular to the film plane. An RFe2 phase is formed in the sample annealed at 550℃ and the residual phases observed are Fe and rare earth oxide. The magnetic properties Hc and Mr/Ms of the film annealed at 550℃ obtain the maximum values,for which the formation of the RFe2 phase is mainly responsible. An annealing treatment leads to a rotation of the sample’s easy axis from being parallel to the film surface to becoming vertical.
基金the University Grants Commission(UGC),New Delhi(File No. F.40-419/2011(SR)) for providing the financial assistance to carry out the above work
文摘The NiO-Cu composite films were deposited on a glass substrate at various substrate temperatures by DC reactive magnetron sputtering technique. The effect of substrate temperature on the structural, optical, morphological and electrical properties of the films was mainly investigated. X-ray diffraction studies revealed that when the substrate temperature increased to above 200 ℃, the preferred orientation tended to move to another preferred site from （220） to （111） and had a band gap values increased with increasing substrate observed that the grain size and root mean square stable cubic structure. The optical transmittance and temperature. From the morphological studies, it was roughness were increased with increasing substrate temperature. The electrical resistivity of the film decreased to 0.017 Ωcm at high substrate temperature of 400 ℃.
基金supported by the Natural Science Foun-dation of China (Grant Nos 60676041 and 10778701)
文摘Transparent conducting molybdenum-doped zinc oxide （MZO） films were successfully prepared by radio frequency （RF） magnetron sputtering method on glass substrates under different substrate temperatures. The nature of MZO film is polycrystalline with hexagonal structure and a preferred orientation along c-axis. With increasing substrate temperature from room temperature to 400℃, the crystallinity of the films is deteriorated and the resistivity increases sharply due to both the decrease of carrier concentration and Hall mobility. The lowest resistivity achieved is 9.2×10^-4 Ω· cm with a high Hall mobility of 30 cm^2·V^-1·s^-1 for the film deposited at room temperature. The average transmttance in the visible range exceeds 85% for all the samples. The optical band gap decreases from 3.30 to 3.25 eV with substrate temperature from room temperature to 400℃.
基金supported by the MOST of China(No.2010CB631301 and 2012CBA01207)NSFC(No.U1201241,11375020 and 21321001)
文摘Pd-capped Mg78Y22 thin films have been prepared by direct current magnetron co-sputtering system at different substrate temperatures and their electrochemical hydrogen storage properties have been investigated.It is found that rising substrate temperature to 60 ℃ can coarsen the surface of thin film,thus facilitating the diffusion of hydrogen atoms and then enhancing its discharge capacity to 1725 mAh·g-1.Simultaneously,the cyclic stability is effectively improved due to the increased adhesion force between film and substrate as a function of temperature.In addition,the specimen exhibits a very long and flat discharge plateau at about —0.67 V,at which nearly 60%of capacity is maintained.The property is favorable for the application in metal hydride/nickel secondary batteries.The results indicate that rising optimal substrate temperature has a beneficial effect on the electrochemical hydrogen storage of Mg-Y thin films.
基金Hi-tech Research and Development Program of China (2002AA763020)National Natural Science Foundation of China (50304007)+1 种基金Fund of Beforehand Research of National Defense (51418040304HT0114)New Century Excellent Talents in University 2004
文摘The 2D kinetic Monte Carlo （KMC） simulation was used to study the effects of different substrate temperatures on the microstructure of Ni-Cr films in the process of deposition by the electron beam physical vapor deposition （EB-PVD）. In the KMC model, substrate was assumed to be a ＂surface＂ of tight-packed rows, and the simulation includes two phenomena： adatom-surface collision and adatom diffusion. While the interaction between atoms was described by the embedded atom method, the jumping energy was calculated by the molecular static （MS） calculation. The initial location of the adatom was defined by the Momentum Scheme. The results reveal that there exists a critical substrate temperature which means that the lowest packing density and the highest surface roughness structure will be achieved when the temperature is lower than the smaller critical value, while the roughness of both surfaces and the void contents keep decreasing with the substrate temperature increasing until it reaches the higher critical value. The results also indicate that the critical substrate temperature rises as the deposition rate increases.
基金the National Natural Science Foundation of China for the financial support under the contract Nos.50275076 and 50605032.
文摘The contacting interface between the substrate and water-cooled base is vital to the substrate temperature during diamond films deposition by a DC （direct current） plasma jet. The effects of the solid contacting area,conductive materials and fixing between the substrate and the base were investigated without affecting the other parameters. Experimental results indicated that the preferable solid contacting area was more than 60% of total contacting areal; the particular Sn-Pb alloy was more suitable for conducting heat and the concentric fixing ring was a better setting for controlling the substrate temperature. The result was explained in terms of the variable thermal contact resistance at the interface between substrate and base. The diamond films were analyzed by scanning electron microscopy （SEM） for morphology, X-ray diffraction （XRD） for the intensity of characteristic spectroscopy and Raman spectroscopy for structure.
文摘Permalloy Ni80Fe20 films have been grown on thermal oxidized Si (111) wafers by magnetron sputtering at well-controlled substrate temperatures of 300, 500, 640 and 780 K in 0.65 Pa argon pressure. The base pressure was about 1×10-4 Pa. The deposition rate was about 5 nm/min for all the films. The structure of the films was studied using X-ray diffraction, scanning electron microscopy and atomic force microscopy. The composition of the films was analyzed using scanning Auger microprobe. The resistance and magnetoresistance of the films were measured using four-point probe technique. The results show that the content of oxygen in the films decreases gradually with raising substrate temperature. In addition, the surface morphology of the films presents notable change with the increasing of the substrate temperature; the residual gases and defects decrease and the grains have coalesced evidently, and then the grains have grown up obviously and the texture of (111) orientation develops gradually in the growing film. As a result, the resistivity reduces apparently and magnetoresistance ratio increases markedly with raising substrate temperature.
文摘TiO2-CeO2 films were deposited on soda-lime glass substrates at varied substrate temperatures by rf magnetron sputtering using 40% molar TiO2-60% molar CeO2 ceramic target in Ar：O2=95：5 atmosphere.The structure,surface composition,UV-visible spectra of the films were measured by scanning electron microscopy and X-ray diffraction,and X-ray photoelectron spectroscopy,respectively.The experimental results show that the films are amorphous,there are only Ti^4＋ and Ce^4＋ on the surface of the films,the obtained TiO2-CeO2 films shou a good uniformity and high densification,and the films deposited on the glass can shield ultraviolet light without significant absorpition of visible light,the films deposited on substrates at room temperature and 220℃ absorb UV effectively.
基金Supported by the National Natural Science Foundation of China under Grant No 11374114
文摘Ta-doped titanium dioxide films are deposited on fused quartz substrates using the rf magnetron sputtering technique at different substrate temperatures. After post-annealing at 550℃ in a vacuum, all the films are crystallized into the polycrystalline anatase TiO2 structure. The effects of substrate temperature from room temperature up to 350℃ on the structure, morphology, and photoelectric properties of Ta-doped titanium dioxide films are analyzed. The average transmittance in the visible region（400-800 nm） of all films is more than 73%.The resistivity decreases firstly and then increases moderately with the increasing substrate temperature. The polycrystalline film deposited at 150℃ exhibits a lowest resistivity of 7.7 × 10^-4Ω·cm with the highest carrier density of 1.1×10^21 cm^-3 and the Hall mobility of 7.4 cm^2·V^-1s^-1.
文摘The effects of the substrate temperature on the deposition and microstructure of the 304 stainless steel （SS） cold gas dynamic spraying （CGDS） coatings were investigated. It was found that the higher substrate temperature could increase the deposition rate of the 304 SS particles,even the oxide films existed at the interface. There was a critical oxide film with a thickness of 3 -4 um which could be destroyed by the impacted particles. The micro-hardness and microstructure of the 304 SS coatings under different substrate preheating temperatures were almost the same.
基金Funded by Key Natural Science Foundation of China Minis-try of Education and Natural Science Foundation for Key Teacher (No.99087).
文摘Transparent TiO2/TiN/TiO2 multi-layer solar control coatings were prepared on normal soda-lime-silica float glass substrate by using d.c. reactive magnetron sputtering at substrate temperature ranging from room temperature to 620℃ . The dependence of optical properties of the coatings and the coating composition, on the substrate temperature was studied. The results of the optical properties show that as the substrate temperature increases, a visible transmittance as high as 65% can be obtained. When the substrate temperature is higher than 370℃ , the infrared reflectance decreases. The results of X-ray photoelectron spectroscopy (XPS) show that when the substrate temperature is higher than 520℃ in oxygen atmosphere, the formation of thin surface over-layers (TiNxOy,) on top of the TiN films can be observed. When the substrate temperature is at 62℃ , the oxynitride become TiO2, which results in the optical degradation of TiN layer in infrared reflectance.
文摘Polycrystalline silicon （poly-Si） films were deposited using Ar diluted SiH4 gaseous mixture by electron cyclotron resonance plasma-enhanced chemical vapor deposition （ECR-PECVD）. The effects of the substrate temperature on deposition rate, crystallinity, grain size and the configuration of H existing in poly-Si film were investigated. The results show that, comparing with H2 dilution, Ar dilution could significantly decrease the concentration of H on the growing surface. When the substrate temperature increased, the deposition rate increased and the concentration of H decreased monotonously, but the crystallinity and the grain size of poly-Si films exhibited sophisticated trends. It is proposed that the crystallinity of the films is determined by a competing balance of the self-diffusion activity of Si atoms and the deposition rate. At substrate temperature of 200℃, the deposited film exhibits the maximum poly-Si volume fraction of 79%. Based on these results, higher substrate temperature is suggested to prepare the poly-Si films with advanced stability and compromised crystallinity at high deposition rate.
基金Funded by the International Science and Technology Cooperation Project (No.2009DFB50470)the National Nature Science Foundation of China (No.50802071)International Science and Technology Cooperation Project of Hubei Province (No.2010BFA017)
文摘MgO thin films were deposited on Si（100） substrates by laser ablation under various substrate temperatures （Tsub）,expecting to provide a candidate buffer layer for the textured growth of functional perovskite oxide films on Si substrates.The effect of Tsub on the preferred orientation,crystallinity and surface morphology of the films was investigated.MgO films in single-phase were obtained at 473-973 K.With increasing Tsub,the preferred orientation of the films changed from （200） to （111）.The crystallinity and surface morphology was different too,depending on Tsub.At Tsub=673 K,the MgO film became uniform and smooth,exhibiting high crystallinity and a dense texture.
基金This work is supported by the National Natural Srience Foundation of China(No.69876025 and No.60076006)Science and Technology Committee of Shandong Province and the Natural Science Foundation of Shandong Province.
文摘This paper presents the substrate temperature dependence of opto-electrical properties for transparent conducting Al-doped ZnO films prepared on polyisocyanate (PI) substrates by r f sputtering. Polycrystalline ZnO:Al films with good adherence to the substrates having a (002) preferred orientation have been obtained with resistivities in the range from 4.1×10-3to 5.3×104 Ωcm, carrier densities more than 2.6×1020 cm-3 and Hall mobilities between 5.78 and 13.11 cm2/V/s for films. The average transmittance reaches 75% in the visible spectrum. The quality of obtained films depends on substrate temperature during film fabrication.
文摘Superconducting thin films of YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-x</sub>（Y-Ba-Cu-O） with Tc more than 85K have been deposited in situ by metalorganic chemical vapor deposition （MOCVD） on yttria stabilized zirconia（YSZ） substrates. The relationship of film orientation on substrate temperature and the lowest formation temperature region of superconducting phase have been obtained after changing the substrate temperature. The epitaxial relation between Y-Ba-Cu-O films and the YSZ su bstrates were discussed.
基金Sponsored by the National Natural Science Foundation of China ( Grant No. 50525204 and 50832001)the special Ph.D. Program ( Grant No.200801830025) from MOE+2 种基金the "211" and "985" Project of Jilin University, Chinathe program for Changjiang Scholars and Innovative Research Teamin UniversityScience Frontier and Cross-disciplinary Innovation Project of Jilin University, China (Grant No. 200903022)
文摘To explore the relationship between the chemical bonding and mechanical properties for germanium carbide (Ge1-xCx) films,the Ge1-xCx films are prepared via reactive magnetron sputtering in a mixture of CH4/Ar discharge,and their composition,chemical bonding and hardness were investigated as a function of substrate temperature (Ts). The results show that Ts remarkably influences the chemical bonding of Ge1-xCx film,which results in a pronounced change in the film hardness. As Ts increases from ambient (60 ℃) to 500 ℃,the Ge content in the film gradually increases,which promotes forming sp3 C-Ge bonds in the film at the expense of sp2C-C bonds. Furthermore,it is found that with increasing Ts the fraction of C-H bonds in Ge1-xCx film gradually decreases,which is attributed to an enhancement in the desorption rate of C-Hn(n=1,2,3) species decomposed from methane. The transition from graphite-like sp2 C-C to diamond-like sp3C-Ge bonds as well as the reduction in C-H bonds in the film with increasing Ts promotes forming the compact three-dimensional network structure,which significantly enhances the hardness of the film from 5.8 to 10.1 GPa.
基金Nature Science Foundation of Jiangsu Province, P.R.China
文摘Amorphous hydrogenated carbon thin films have been deposited with benzene plasma in an electron cyclotron resonance (ECR) plasma enhanced chemical vapor deposition system. The characteristic of Benzene discharge plasma has been monitored by Mast spectrometry. It shows that the majority of the plasma species in the downstream ECR Plasma with benzene as gas source are acetylene, ethylene and higher mass species. In the experiments, the effects of the substrate temperature on the deposition rates have been emphatically studied. The structures of the films were analyzed by FTIR and Ramam spectrum.The results show that when the substrate temperature rises, the deposition rate drops down, the hydrogen Foment decreases, with the higher SP3 content being presented in the film.
基金The Distinguished Youth Foundation of Hunan Province(03JJY1008)The Natural Science Foundation of Hunan Province(06JJ2034)
文摘Due to their particular optical characteristics,metallic island films have the potential to significantly increase the energy conversion efficiency of solar cell.We experimentally and theoretically investigated the effect of substrate temperature on the morphologies and optical properties of the silver island films.At low temperature,below 300 ℃,as the substrate temperature increases.Compared to the films prepared at room temperature,the sizes of nanoparticles decrease and the Absorption peaks shift to shorter wavelength accompanied by an increase density resulting in a 150% Absorption efficiency.As the substrate temperature goes up to 300 ℃,nanoparticles with larger in-plan(X-Y)dimensions are formed,the number density decreases and the Absorption peaks redshift but the Absorption efficiency is still 10% higher.Numerical simulation reveals that these behaviors are a consequence of morphologies transformation.
