As a potential ferromagnetic shape memory alloy, Ni-Co-Al has excellent mechanical properties, large ma gentic-field-induced strain and high martensitic transformation temperature. The relationship between microstruct...As a potential ferromagnetic shape memory alloy, Ni-Co-Al has excellent mechanical properties, large ma gentic-field-induced strain and high martensitic transformation temperature. The relationship between microstructure and performance （mechanical and magnetic properties） of Ni-Co-Al with different Co/Al atomic ratios （RCo/Al） was investigated. Samples exhibit β and γ dual-phase structure. The γ phase grows coarse and the volume fraction of γ phase increases with the rise of RCo/Al. Besides, sample with high amount of γ phase content has smaller βgrains ow- ing to the pinning effect of γ phase. The martensite, transformed from β phase, is tetragonal L10 structure with a （111） twinning plane. The martensitic transformation temperature of samples ascends with increasing R co/Al owing to more Co embedded into the cell, which makes the valence electron concentration （e/a） of system rise. The satura- tion magnetization （Ms） of samples increases as Rco/Al rises because Co-rich 7 phase has excellent magnetic property. Meanwhile, both compressive and micro-hardness tests reveal that the samples containing more γ phase have excel- lent ductility due to the intrinsic good ductility nature of γ phase.展开更多
Chemical and field-effect passivation of atomic layer deposition （ALD） Al2O3 films are investigated, mainly by corona charging measurement. The interface structure and material properties are characterized by transm...Chemical and field-effect passivation of atomic layer deposition （ALD） Al2O3 films are investigated, mainly by corona charging measurement. The interface structure and material properties are characterized by transmission electron microscopy （TEM） and X-ray photoelectron spectroscopy （XPS）, respectively. Passivation performance is improved remarkably by annealing at temperatures of 450 ℃ and 500 ℃, while the improvement is quite weak at 600 ℃, which can be attributed to the poor quality of chemical passivation. An increase of fixed negative charge density in the films during annealing can be explained by the Al2O3/Si interface structural change. The Al–OH groups play an important role in chemical passivation, and the Al–OH concentration in an as-deposited film subsequently determines the passivation quality of that film when it is annealed, to a certain degree.展开更多
According to probability theory and atomic activation on bonding interface of metals, a mathematical model was developed for the atomic interfacial reaction during diffusion bonding.The effect of parameters of bonding...According to probability theory and atomic activation on bonding interface of metals, a mathematical model was developed for the atomic interfacial reaction during diffusion bonding.The effect of parameters of bonding processing and material on the bonding strength was then gained.It was suggested that the activation centre of atomic interfacial reaction of bonding may be,in situ,the boundary dislocation and its elastic stress field. A substantial agreement about the quantitative prediction of the model was made with the results of diffusion bonding experiments for 7075Al alloy展开更多
A slightly modified central atoms model was proposed. The probabilities of various clusters with the central atoms and their nearest neighboring shells can be calculated neglecting the assumption of the parameter of e...A slightly modified central atoms model was proposed. The probabilities of various clusters with the central atoms and their nearest neighboring shells can be calculated neglecting the assumption of the parameter of energy in the central atoms model in proportion to the number of other atoms i (referred with the central atom). A parameter P α is proposed in this model, which equals to reciprocal of activity coefficient of α component, therefore, the new model can be understood easily. By this model, the Al Zn phase diagram and its thermodynamic properties were calculated, the results coincide with the experimental data.展开更多
In this paper,to overcome the issues of high roughness and defect density in(001)β-Ga_(2)O_(3)epitaxial films grown by MOCVD,a novel in-situ pulsed Al atom assisted growth method is proposed.Compared to films grown b...In this paper,to overcome the issues of high roughness and defect density in(001)β-Ga_(2)O_(3)epitaxial films grown by MOCVD,a novel in-situ pulsed Al atom assisted growth method is proposed.Compared to films grown by conventional growth methods,theβ-Ga_(2)O_(3)epitaxial film grown using this method exhibited lower RMS roughness and a smaller FWHM of the(002)peak in the X-ray rocking curve.Additionally,oxygen vacancy defects within the film are significantly reduced,and Al incorporation is relatively limited without inducing lattice distortion.The width of serrations at the substrate-epitaxial layer interface is reduced from 70 nm to 17 nm,demonstrating improved interface flatness.The mechanism of pulsed Al atoms in optimizing homoepitaxial growth of(001)β-Ga_(2)O_(3)is proposed,including their roles as preferential nucleation sites for Ga atoms,their inhibitory effects on Ga_(2)O formation and desorption,and the enhancement of atomic diffusion while minimizing parasitic side reactions.The phenomenon of epitaxial orientation rotation is observed,and a hypothesis is proposed regarding the causes of the difference in rotation angle and surface flatness.Additionally,Schottky barrier diodes(SBDs)are also fabricated to study the electrical properties of these epitaxial materials.The epitaxial layer obtained through the pulsed Al atom assisted growth method exhibited a breakdown field strength of 1.8 MV/cm.These results demonstrate that the pulsed Al atom assisted growth method may serve as a valuable reference for achieving high-quality(001)β-Ga_(2)O_(3)epitaxial growth by the MOCVD method.展开更多
The growth of single-crystalα-Al_(2)O_(3) is crucial for a variety of applications in electronics and other fields,while the synthesis of its two-dimensional(2D)form is not easy due to the high activation energy.Here...The growth of single-crystalα-Al_(2)O_(3) is crucial for a variety of applications in electronics and other fields,while the synthesis of its two-dimensional(2D)form is not easy due to the high activation energy.Here,we demonstrate the growth of single-crystal 2Dα-Al_(2)O_(3) by high temperature(high-T)annealing of Ni foils.Tens of micrometers of 2Dα-Al_(2)O_(3) flakes grow on the surface of Ni foils,which is attributed to the precipitation of Al atoms from the Ni foil bulk to its surface,followed by the oxidation of Al atoms on the surface.In principle,the Ni foil acts as a solvent,where diluted metal atoms precipitate onto the surface and react with oxygen from the atmosphere to grow single-crystal 2D metal oxides.Our findings may also provide a promising method for synthesizing other single-crystal 2D metal oxides.展开更多
Al2O3and HfO2thin films are separately deposited on n-type InAlAs epitaxial layers by using atomic layer deposition(ALD).The interfacial properties are revealed by angle-resolved x-ray photoelectron spectroscopy(AR-XP...Al2O3and HfO2thin films are separately deposited on n-type InAlAs epitaxial layers by using atomic layer deposition(ALD).The interfacial properties are revealed by angle-resolved x-ray photoelectron spectroscopy(AR-XPS).It is demonstrated that the Al2O3layer can reduce interfacial oxidation and trap charge formation.The gate leakage current densities are 1.37×106A/cm2and 3.22×106A/cm2at+1V for the Al2O3/InAlAs and HfO2/InAlAs MOS capacitors respectively.Compared with the HfO2/InAlAs metal-oxide-semiconductor(MOS) capacitor,the Al2O3/InAlAS MOS capacitor exhibits good electrical properties in reducing gate leakage current,narrowing down the hysteresis loop,shrinking stretch-out of the C-V characteristics,and significantly reducing the oxide trapped charge(Qot) value and the interface state density(Dit).展开更多
The atomic structure and transition properties of H-like Al embedded in hot and dense plasmas are investigated using modified GRASP2 K code. The plasma screening effect on the nucleus is described using the self-consi...The atomic structure and transition properties of H-like Al embedded in hot and dense plasmas are investigated using modified GRASP2 K code. The plasma screening effect on the nucleus is described using the self-consistent field ion sphere model. The effective nuclear potential decreases much more quickly with increasing average free electron density,but increases slightly with increasing electron temperature. The variations of the transition energies, transition probabilities,and oscillator strengths with the free electron density and electron temperature are the same as that of the effective nuclear potential. The results reported in this work agree well with other available theoretical results and are useful for plasma diagnostics.展开更多
The bulk specimens with preferable orientation were utilized to investigate atom exchange of martensite in Cu-13Zn-15Al alloy during non-isothermal aging by in-situ X-ray diffraction. It is found that the exchange of ...The bulk specimens with preferable orientation were utilized to investigate atom exchange of martensite in Cu-13Zn-15Al alloy during non-isothermal aging by in-situ X-ray diffraction. It is found that the exchange of Zn atoms at position Ⅲ and Cu atoms at Ⅱ and the exchange of Zn atoms at position Ⅲ and Al atoms atⅠon the basal plane of martensite occur during heating at a heating rate of 5 ℃/min. 13% (2/25 ) of Al atoms transfer from positionⅠto position Ⅲ when temperature goes up to 160 ℃.展开更多
Al-20Sn-1Cu powders were prepared by gas atomization in an argon atmosphere with atomizing pressures of 1.1 and 1.6 MPa. The characteristics of the powders are determined by means of dry sieving, scanning electron mic...Al-20Sn-1Cu powders were prepared by gas atomization in an argon atmosphere with atomizing pressures of 1.1 and 1.6 MPa. The characteristics of the powders are determined by means of dry sieving, scanning electron microscopy （SEM）, optical microscopy （OM）, and X-ray diffractometry （XRD）. The results show that the powders exhibit a bimodal size distribution and a higher gas pressure results in a broad size distribution. All particles in both cases are spherical or nearly spherical and satellites form on the surface of coarse particles. Dendritic and cellular structures coexist in the particle. With decreasing particle diameter, the secondary dendrite arm spacing （SDAS） decreases and the cooling rate increases. The particles processed under high gas atomization pressure （1.6 MPa） exhibit a lower SDAS value and a higher cooling rate than those of the same size under low gas atomization pressure （1.1 MPa）. The XRD results show that the Sn content increases with decreasing particle size.展开更多
In this study, 6061 aluminum alloy and AZ31 B magnesium alloy composite plate was fabricated through explosive welding. Molecular dynamics（MD） simulations were conducted to investigate atomic diffusion behavior at b...In this study, 6061 aluminum alloy and AZ31 B magnesium alloy composite plate was fabricated through explosive welding. Molecular dynamics（MD） simulations were conducted to investigate atomic diffusion behavior at bonding interface in the AI/Mg composite plate. Corresponding experiments were conducted to validate the simulation results. The results show that diffusion coefficient of Mg atom is larger than that of A1 atom and the difference between these two coefficients becomes smaller with increasing collision velocity. The diffusion coefficient was found to depend on collision velocity and angle. It increases linearly with collision velocity when the collision angle is maintained constant at 10° and decreases linearly with collision angle when the collision velocity is maintained constantly at 440 m/s. Based on our MD simulation results and Fick＇s second law, a mathematical formula to calculate the thickness of diffusion layer was proposed and its validity was verified by relevant experiments. Transmission electron microscopy and energy-dispersive system were also used to investigate the atomic diffusion behavior at the bonding interface in the explosively welded 6061/AZ31B composite plate. The results show that there were obvious Al and Mg atom diffusion at the bonding interface,and the diffusion of magnesium atoms from magnesium alloy plate to aluminum alloy plate occurs much faster than the diffusion of aluminum atoms to the magnesium alloy plate. These findings from the current study can help to optimize the explosive welding process.展开更多
A UHV system specially designed for studying surface and interface atomic structure by MeV ion scattering and channeling is described. The vacuum in the UHV chamber is 133.332×10-10Pa. The chamber is equipped wit...A UHV system specially designed for studying surface and interface atomic structure by MeV ion scattering and channeling is described. The vacuum in the UHV chamber is 133.332×10-10Pa. The chamber is equipped with an ion gun used for sample cleaning, a translatable four-grid LEED-Auger system used for characterization of the crystal surface, and a three dimensional goniometer. The crystal preparation and cleaning procedure of Al(100) are presented. The surface peak intensity of Al(100)-【100】 and Al(100)- 【100】 has been measured by MeV ion channeling and scattering. The measured surface peak intensity was compared with that of Monte-Carlo simulation. The experimental results indicate that the thermal vibration amplitude of Al(100) surface atoms is 1.2 -1.3 times that of bulk atoms. The relaxation of first layer for Al(100) is less than -0.005nm.展开更多
Ordering and atom clustering in aging binary Al-Li alloy has been investigated by computer simulation through calculating the long range order (Iro.) parameter and composition deviation order parameter from single-sit...Ordering and atom clustering in aging binary Al-Li alloy has been investigated by computer simulation through calculating the long range order (Iro.) parameter and composition deviation order parameter from single-site occupation probabilities of Li atom. The results show that when the alloy lies in metastable region in the phase diagram ordering and atom clustering occur simultaneously. As the composition of the alloy increases ordering occurs earlier than atom clustering gradually. When the alloy lies in instable region atom clustering takes place after the congruent ordering completes. It has also been found that the incubation period of the phase transformation is shortened as the composition increases.展开更多
wo different surface morphology characteristics of magnetron sputtered aluminumsilicon(Al-Si)alloy films deposited at 0 and 200℃ were observed by atomic force microscopy(AFM).One is irregularly shaped grains put togt...wo different surface morphology characteristics of magnetron sputtered aluminumsilicon(Al-Si)alloy films deposited at 0 and 200℃ were observed by atomic force microscopy(AFM).One is irregularly shaped grains put togther on a plane.The other is irregularly shaped grains Piled up in space. Nanometer-sized particles with heights from 1.6 to 2.9 nm were first observed. On the basis of these observations the growth mechanism of magnetron sputtered films is discussed.展开更多
文摘As a potential ferromagnetic shape memory alloy, Ni-Co-Al has excellent mechanical properties, large ma gentic-field-induced strain and high martensitic transformation temperature. The relationship between microstructure and performance （mechanical and magnetic properties） of Ni-Co-Al with different Co/Al atomic ratios （RCo/Al） was investigated. Samples exhibit β and γ dual-phase structure. The γ phase grows coarse and the volume fraction of γ phase increases with the rise of RCo/Al. Besides, sample with high amount of γ phase content has smaller βgrains ow- ing to the pinning effect of γ phase. The martensite, transformed from β phase, is tetragonal L10 structure with a （111） twinning plane. The martensitic transformation temperature of samples ascends with increasing R co/Al owing to more Co embedded into the cell, which makes the valence electron concentration （e/a） of system rise. The satura- tion magnetization （Ms） of samples increases as Rco/Al rises because Co-rich 7 phase has excellent magnetic property. Meanwhile, both compressive and micro-hardness tests reveal that the samples containing more γ phase have excel- lent ductility due to the intrinsic good ductility nature of γ phase.
基金Project supported by the National Natural Science Foundation of China(Grant No.61106060)the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.Y2YF028001)the National High Technology Research and Development Program of China(Grant No.2012AA052401)
文摘Chemical and field-effect passivation of atomic layer deposition （ALD） Al2O3 films are investigated, mainly by corona charging measurement. The interface structure and material properties are characterized by transmission electron microscopy （TEM） and X-ray photoelectron spectroscopy （XPS）, respectively. Passivation performance is improved remarkably by annealing at temperatures of 450 ℃ and 500 ℃, while the improvement is quite weak at 600 ℃, which can be attributed to the poor quality of chemical passivation. An increase of fixed negative charge density in the films during annealing can be explained by the Al2O3/Si interface structural change. The Al–OH groups play an important role in chemical passivation, and the Al–OH concentration in an as-deposited film subsequently determines the passivation quality of that film when it is annealed, to a certain degree.
文摘According to probability theory and atomic activation on bonding interface of metals, a mathematical model was developed for the atomic interfacial reaction during diffusion bonding.The effect of parameters of bonding processing and material on the bonding strength was then gained.It was suggested that the activation centre of atomic interfacial reaction of bonding may be,in situ,the boundary dislocation and its elastic stress field. A substantial agreement about the quantitative prediction of the model was made with the results of diffusion bonding experiments for 7075Al alloy
文摘A slightly modified central atoms model was proposed. The probabilities of various clusters with the central atoms and their nearest neighboring shells can be calculated neglecting the assumption of the parameter of energy in the central atoms model in proportion to the number of other atoms i (referred with the central atom). A parameter P α is proposed in this model, which equals to reciprocal of activity coefficient of α component, therefore, the new model can be understood easily. By this model, the Al Zn phase diagram and its thermodynamic properties were calculated, the results coincide with the experimental data.
基金supported by the National Natural Science Foundation of China under Grant Nos.62474133 and U2241220the opening project of state key laboratory of wide bandgap semiconductor devices and integrated technology under Grant No.2413S111the fundamental research funds for the central universities of China under Grant Nos.QTZX23019 and ZDRC2002.
文摘In this paper,to overcome the issues of high roughness and defect density in(001)β-Ga_(2)O_(3)epitaxial films grown by MOCVD,a novel in-situ pulsed Al atom assisted growth method is proposed.Compared to films grown by conventional growth methods,theβ-Ga_(2)O_(3)epitaxial film grown using this method exhibited lower RMS roughness and a smaller FWHM of the(002)peak in the X-ray rocking curve.Additionally,oxygen vacancy defects within the film are significantly reduced,and Al incorporation is relatively limited without inducing lattice distortion.The width of serrations at the substrate-epitaxial layer interface is reduced from 70 nm to 17 nm,demonstrating improved interface flatness.The mechanism of pulsed Al atoms in optimizing homoepitaxial growth of(001)β-Ga_(2)O_(3)is proposed,including their roles as preferential nucleation sites for Ga atoms,their inhibitory effects on Ga_(2)O formation and desorption,and the enhancement of atomic diffusion while minimizing parasitic side reactions.The phenomenon of epitaxial orientation rotation is observed,and a hypothesis is proposed regarding the causes of the difference in rotation angle and surface flatness.Additionally,Schottky barrier diodes(SBDs)are also fabricated to study the electrical properties of these epitaxial materials.The epitaxial layer obtained through the pulsed Al atom assisted growth method exhibited a breakdown field strength of 1.8 MV/cm.These results demonstrate that the pulsed Al atom assisted growth method may serve as a valuable reference for achieving high-quality(001)β-Ga_(2)O_(3)epitaxial growth by the MOCVD method.
基金supported by Shenzhen Science and Technology Program(No.KQTD20200820113010022).
文摘The growth of single-crystalα-Al_(2)O_(3) is crucial for a variety of applications in electronics and other fields,while the synthesis of its two-dimensional(2D)form is not easy due to the high activation energy.Here,we demonstrate the growth of single-crystal 2Dα-Al_(2)O_(3) by high temperature(high-T)annealing of Ni foils.Tens of micrometers of 2Dα-Al_(2)O_(3) flakes grow on the surface of Ni foils,which is attributed to the precipitation of Al atoms from the Ni foil bulk to its surface,followed by the oxidation of Al atoms on the surface.In principle,the Ni foil acts as a solvent,where diluted metal atoms precipitate onto the surface and react with oxygen from the atmosphere to grow single-crystal 2D metal oxides.Our findings may also provide a promising method for synthesizing other single-crystal 2D metal oxides.
基金supported by the National Basic Research Program of China(Grant No.2010CB327505)the Advanced Research Foundation of China(Grant No.914xxx803-051xxx111)+3 种基金the National Defense Advance Research Project,China(Grant No.513xxxxx306)the National Natural Science Foundation of China(Grant No.51302215)the Scientific Research Program Funded by Shaanxi Provincial Education Department,China(Grant No.14JK1656)the Science and Technology Project of Shaanxi Province,China(Grant No.2016KRM029)
文摘Al2O3and HfO2thin films are separately deposited on n-type InAlAs epitaxial layers by using atomic layer deposition(ALD).The interfacial properties are revealed by angle-resolved x-ray photoelectron spectroscopy(AR-XPS).It is demonstrated that the Al2O3layer can reduce interfacial oxidation and trap charge formation.The gate leakage current densities are 1.37×106A/cm2and 3.22×106A/cm2at+1V for the Al2O3/InAlAs and HfO2/InAlAs MOS capacitors respectively.Compared with the HfO2/InAlAs metal-oxide-semiconductor(MOS) capacitor,the Al2O3/InAlAS MOS capacitor exhibits good electrical properties in reducing gate leakage current,narrowing down the hysteresis loop,shrinking stretch-out of the C-V characteristics,and significantly reducing the oxide trapped charge(Qot) value and the interface state density(Dit).
基金supported by the National Natural Science Foundation of China(Grant Nos.11474208 and 11565018)the Department of Education Fund Item of Gansu Province,China(Grant No.2015B-109)the Doctoral Scientific Fund Project of Longdong University,China(Grant No.XYBY1601)
文摘The atomic structure and transition properties of H-like Al embedded in hot and dense plasmas are investigated using modified GRASP2 K code. The plasma screening effect on the nucleus is described using the self-consistent field ion sphere model. The effective nuclear potential decreases much more quickly with increasing average free electron density,but increases slightly with increasing electron temperature. The variations of the transition energies, transition probabilities,and oscillator strengths with the free electron density and electron temperature are the same as that of the effective nuclear potential. The results reported in this work agree well with other available theoretical results and are useful for plasma diagnostics.
基金Project(05JJ3005) supported by the Natural Science Foundation of Hunan Province, China Project(20040553069) supported by the PhD Programs of Ministry of Education of China
文摘The bulk specimens with preferable orientation were utilized to investigate atom exchange of martensite in Cu-13Zn-15Al alloy during non-isothermal aging by in-situ X-ray diffraction. It is found that the exchange of Zn atoms at position Ⅲ and Cu atoms at Ⅱ and the exchange of Zn atoms at position Ⅲ and Al atoms atⅠon the basal plane of martensite occur during heating at a heating rate of 5 ℃/min. 13% (2/25 ) of Al atoms transfer from positionⅠto position Ⅲ when temperature goes up to 160 ℃.
基金the Major State Ba-sic Research Development Program of China (Nos. 2006CB605203 and 2006CB605204)
文摘Al-20Sn-1Cu powders were prepared by gas atomization in an argon atmosphere with atomizing pressures of 1.1 and 1.6 MPa. The characteristics of the powders are determined by means of dry sieving, scanning electron microscopy （SEM）, optical microscopy （OM）, and X-ray diffractometry （XRD）. The results show that the powders exhibit a bimodal size distribution and a higher gas pressure results in a broad size distribution. All particles in both cases are spherical or nearly spherical and satellites form on the surface of coarse particles. Dendritic and cellular structures coexist in the particle. With decreasing particle diameter, the secondary dendrite arm spacing （SDAS） decreases and the cooling rate increases. The particles processed under high gas atomization pressure （1.6 MPa） exhibit a lower SDAS value and a higher cooling rate than those of the same size under low gas atomization pressure （1.1 MPa）. The XRD results show that the Sn content increases with decreasing particle size.
基金financially supported by the National Natural Science Foundation of China (No.51375328)
文摘In this study, 6061 aluminum alloy and AZ31 B magnesium alloy composite plate was fabricated through explosive welding. Molecular dynamics（MD） simulations were conducted to investigate atomic diffusion behavior at bonding interface in the AI/Mg composite plate. Corresponding experiments were conducted to validate the simulation results. The results show that diffusion coefficient of Mg atom is larger than that of A1 atom and the difference between these two coefficients becomes smaller with increasing collision velocity. The diffusion coefficient was found to depend on collision velocity and angle. It increases linearly with collision velocity when the collision angle is maintained constant at 10° and decreases linearly with collision angle when the collision velocity is maintained constantly at 440 m/s. Based on our MD simulation results and Fick＇s second law, a mathematical formula to calculate the thickness of diffusion layer was proposed and its validity was verified by relevant experiments. Transmission electron microscopy and energy-dispersive system were also used to investigate the atomic diffusion behavior at the bonding interface in the explosively welded 6061/AZ31B composite plate. The results show that there were obvious Al and Mg atom diffusion at the bonding interface,and the diffusion of magnesium atoms from magnesium alloy plate to aluminum alloy plate occurs much faster than the diffusion of aluminum atoms to the magnesium alloy plate. These findings from the current study can help to optimize the explosive welding process.
文摘A UHV system specially designed for studying surface and interface atomic structure by MeV ion scattering and channeling is described. The vacuum in the UHV chamber is 133.332×10-10Pa. The chamber is equipped with an ion gun used for sample cleaning, a translatable four-grid LEED-Auger system used for characterization of the crystal surface, and a three dimensional goniometer. The crystal preparation and cleaning procedure of Al(100) are presented. The surface peak intensity of Al(100)-【100】 and Al(100)- 【100】 has been measured by MeV ion channeling and scattering. The measured surface peak intensity was compared with that of Monte-Carlo simulation. The experimental results indicate that the thermal vibration amplitude of Al(100) surface atoms is 1.2 -1.3 times that of bulk atoms. The relaxation of first layer for Al(100) is less than -0.005nm.
文摘Ordering and atom clustering in aging binary Al-Li alloy has been investigated by computer simulation through calculating the long range order (Iro.) parameter and composition deviation order parameter from single-site occupation probabilities of Li atom. The results show that when the alloy lies in metastable region in the phase diagram ordering and atom clustering occur simultaneously. As the composition of the alloy increases ordering occurs earlier than atom clustering gradually. When the alloy lies in instable region atom clustering takes place after the congruent ordering completes. It has also been found that the incubation period of the phase transformation is shortened as the composition increases.
基金Acknowledgment： This work was financially supported by the Natural Science Foundation of China （No. 50661001 and 50061001） and the Science Foundation of Guangxi Province （No. 0832029 and 0639004）.
文摘wo different surface morphology characteristics of magnetron sputtered aluminumsilicon(Al-Si)alloy films deposited at 0 and 200℃ were observed by atomic force microscopy(AFM).One is irregularly shaped grains put togther on a plane.The other is irregularly shaped grains Piled up in space. Nanometer-sized particles with heights from 1.6 to 2.9 nm were first observed. On the basis of these observations the growth mechanism of magnetron sputtered films is discussed.
