In order to study the effects of aging treatment on the intergranular corrosion(IGC) and stress corrosion cracking(SCC) of 7003 aluminum alloy(AA7003), the intergranular corrosion test, electrochemical test and slow s...In order to study the effects of aging treatment on the intergranular corrosion(IGC) and stress corrosion cracking(SCC) of 7003 aluminum alloy(AA7003), the intergranular corrosion test, electrochemical test and slow strain rate test(SSRT), combined with optical microscopy(OM) and scanning electron microscopy(SEM) as well as transmission electron microscopy(TEM) observations have been carried out. The IGC and electrochemical test results showed that the IGC resistance of AA7003 for peak aged(PA) temper is the lowest, with double peak aged(DPA) the moderate, and retrogression and re-aging(RRA) the highest among three tempers, which is attributed to the continuous feature of precipitation on grain boundary of PA temper and the interrupted feature of precipitation on grain boundary of DPA and RRA tempers, as well as the wide precipitation free zones(PFZ) of RRA temper. In addition, the SSRT results indicated that all three tempers AA7003 are susceptible to SCC in IGC solution, and the change tendency of SCC susceptibility(ISCC) of AA7003 for three tempers follows the order: ISCC(RRA)<ISCC(DPA)<ISCC(PA).展开更多
The passive film-induced stress and the susceptibility to SCC of 7050 aluminum alloy in 3.5%sodium chloride solution at various pH values were investigated by slow strain rate testing(SSRT) and flowing stress differen...The passive film-induced stress and the susceptibility to SCC of 7050 aluminum alloy in 3.5%sodium chloride solution at various pH values were investigated by slow strain rate testing(SSRT) and flowing stress differential method.The results showed that the passive film-induced stress and the susceptibility to SCC decreased with increasing pH values when pH≤7,while they increased with increasing pH values when pH>7.However,the corrosion type was interpreted as exfoliation corrosion when pH=l and 14,and there was no film formed on the surface of the specimens.The whole variation plots of film-induced stress and the SCC susceptibility with pH values were both presented as a valley shape.The symbol and amount of the film-induced stress were related to the compositions of the passive film,which were analyzed using X-ray photoelectron spectroscopy(XPS).展开更多
The effects of Mg on the microstructure and growth kinetics of the hot-dip Zn-22.3 Al-1.1 Si-x Mg(x = 0, 0.2, 0.4, and 0.6) coatings were investigated in detail. Scanning electron microscopy with energy dispersive spe...The effects of Mg on the microstructure and growth kinetics of the hot-dip Zn-22.3 Al-1.1 Si-x Mg(x = 0, 0.2, 0.4, and 0.6) coatings were investigated in detail. Scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction studies revealed the presence of η-Zn, α-Al, Zn/Al eutectoid,(Si), Al/Si eutectic, and Zn/Al/Mg_2 Zn11 ternary eutectic on the top surface of these Mg-containing coatings. Especially, a small amount of MgZn2 phase appears in top surface of Zn-22.3 Al-1.1 Si-0.6 Mg coating. Five phases are found in the alloy layers, i e, Fe_2 Al_5, FeAl_3, τ_(5C), τ_(5H), and τ_1. The addition of 0.2% Mg can delay the emergence of FeAl_3 phase. When the Mg content is more than 0.2%, the outer layers of coating change from τ_(5C) to τ_(5H) phase. The growth of the inhibition layer is diffusion controlled for various Mg content baths. Mg improves the corrosion resistance of the Mg-containing coatings, and the Zn-22.3 Al-1.1 Si-0.6 Mg coating possesses the highest protective properties.展开更多
Plasma electrolytic oxidation(PEO) coatings were fabricated on 6063 aluminum alloy in a cheap and convenient electrolyte. The effect of different current densities, i e, 5, 10, 15, and 20 A/dm^2 on the microstructure ...Plasma electrolytic oxidation(PEO) coatings were fabricated on 6063 aluminum alloy in a cheap and convenient electrolyte. The effect of different current densities, i e, 5, 10, 15, and 20 A/dm^2 on the microstructure and corrosion behavior of coatings was comprehensively studied by scanning electron microscopy(SEM), stereoscopic microscopy, potentiodynamic polarization and electrochemical impedance spectroscopy(EIS), respectively. It is found that the pore density decreases and the pore size increases with increasing current density. The XRD results show that the coatings are only composed of α-Al_2 O_3 and γ-Al_2 O_3. Potentiodynamic polarization test proves that the coating formed under 10 A/dm^2 possesses the best anticorrosion property. The long time EIS test shows that the coating under 10 A/dm^2 is able to protect the aluminum alloy substrate after long time of immersion in 0.59 M NaCl solution, which confirms the salt solution immersion test results in 2 M NaCl solution.展开更多
The effect of the deposition temperature of the buffer layer In_2S_3 on the band alignment of CZTS/In_2S_3 heterostructures and the solar cell performance have been investigated.The In_2S_3 films are prepared by therm...The effect of the deposition temperature of the buffer layer In_2S_3 on the band alignment of CZTS/In_2S_3 heterostructures and the solar cell performance have been investigated.The In_2S_3 films are prepared by thermal evaporation method at temperatures of 30,100,150,and 200 ℃,respectively.By using x-ray photoelectron spectroscopy(XPS),the valence band offsets(VBO) are determined to be-0.28 ±0.1,-0.28 ±0.1,-0.34 ±0.1,and-0.42 ±0.1 eV for the CZTS/In_2S_3heterostructures deposited at 30,100,150,and 200 ℃,respectively,and the corresponding conduction band offsets(CBO)are found to be 0.3 ±0.1,0.41 ±0.1,0.22±0.1,and 0.01 ±0.1 eV,respectively.The XPS study also reveals that interdiffusion of In and Cu occurs at the interface of the heterostructures,which is especially serious at 200 ℃ leading to large amount of interface defects or the formation of CuInS_2 phase at the interface.The CZTS solar cell with the buffer layer In_2S_3 deposited at 150 ℃ shows the best performance due to the proper CBO value at the heterostructure interface and the improved crystal quality of In_2S_3 film induced by the appropriate deposition temperature.The device prepared at 100 ℃presents the poorest performance owing to too high a value of CBO.It is demonstrated that the deposition temperature is a crucial parameter to control the quality of the solar cells.展开更多
A phenomenological Landau–Devonshire theory is developed to investigate the ferroelectric, dielectric, and piezoelectric properties of(110) oriented Pb(Zr_(1-x)Ti_x)O_3(x = 0.4, 0.5, 0.6, and 0.7) thin films. At room...A phenomenological Landau–Devonshire theory is developed to investigate the ferroelectric, dielectric, and piezoelectric properties of(110) oriented Pb(Zr_(1-x)Ti_x)O_3(x = 0.4, 0.5, 0.6, and 0.7) thin films. At room temperature, the tetragonal a_1 phase, the orthorhombic a_2c phase, the triclinic γ_1 phase, and the triclinic γ_2 phase are stable. The appearance of the negative polarization component P_2 in the a_2c phase and the γ_1 phase is attributed to the nonlinear coupling terms in the thermodynamic potential. The γ phase of the Pb(Zr_(1-x)Ti_x)O_3 thin films has better dielectric and piezoelectric properties than the a_2c phase and the a_1 phase. The largest dielectric and piezoelectric coefficients are obtained in the Pb(Zr_(0.5)Ti_(0.5))O_3 thin film. The piezoelectric coefficient of 110–150 pm/V is obtained in the(110) oriented Pb(Zr_(0.5)Ti_(0.5))O_3 thin film, and the Pb(Zr_(0.3)Ti_(0.7))O_3 thin film has the remnant polarization and relative dielectric constant of 50 μC/cm^2 and 100, respectively,which are in agreement with the experimental measurements reported in the literature.展开更多
The helicity-dependent photoconductance of the edge states in three-dimensional topological insulator Bi_(2)Te_(3)films is investigated.It is revealed that the helicity-dependent photoconductivity current on the left ...The helicity-dependent photoconductance of the edge states in three-dimensional topological insulator Bi_(2)Te_(3)films is investigated.It is revealed that the helicity-dependent photoconductivity current on the left edge of the Bi_(2)Te_(3)film shows an opposite sign with that on the right edge.In addition,the helicity-dependent photoconductivity current increases linearly with the applied longitudinal electric field,and it reverses the sign with the reversal of the electric field.As the thickness of the Bi_(2)Te_(3)film increases,the helicity-dependent photoconductivity current also increases.Theoretical analysis suggests that the helicity-dependent photo-conductivity current may come from the intrinsic spin orbit coupling(SOC)or the SOC introduced by the chiral impurities or defects.展开更多
Plasma electrolytic oxidation(PEO) coatings were prepared on AZ31 magnesium alloy using alkaline phosphate as base electrolyte system, and with the addition of sodium silicate(Na_2SiO_3), sodium aluminate(NaAlO_2) and...Plasma electrolytic oxidation(PEO) coatings were prepared on AZ31 magnesium alloy using alkaline phosphate as base electrolyte system, and with the addition of sodium silicate(Na_2SiO_3), sodium aluminate(NaAlO_2) and potassium fluorozirconate(K_2ZrF_6) as additives. The microstructure, phase composition and element composition as well as surface profile of the PEO coatings were analyzed by means of scanning electron microscopy(SEM), X-ray diffraction(XRD), energy dispersive X-ray spectroscopy(EDS), and threedimensional(3 D) optical profilometry. The corrosion and wear properties were evaluated by electrochemical potentiodynamic polarization in 3.5 wt% Na Cl solution and ball-on-disc wear tests, respectively. The results showed that the anions of the additives effectively participated in the coating formation influencing its microstructural features, chemical composition, corrosion resistance and tribological behaviour. It was observed that the sample treated by PEO in the electrolyte solution containing K_2ZrF_6 as an additive showed better corrosion and abrasive resistance.展开更多
Recently,great efforts have been made in the fabrication of arbitrary warped devices to satisfy the requirement of wearable and lightweight electronic products.Direct growth of high crystalline quality films on flexib...Recently,great efforts have been made in the fabrication of arbitrary warped devices to satisfy the requirement of wearable and lightweight electronic products.Direct growth of high crystalline quality films on flexible substrates is the most desirable method to fabricate flexible devices owing to the advantage of simple and compatible preparation technology with current semiconductor devices,while it is a very challenging work,and usually amorphous,polycrystalline or discontinuous single crystalline films are achieved.Here we demonstrate the direct growth of high-quality Bi_2 Te_3 single crystalline films on flexible polyimide substrates by the modified hot wall epitaxy technique.Experimental results reveal that adjacent crystallites are coherently coalesced to form a continuous film,although amounts of disoriented crystallites are generated due to fast growth rate.By inserting a quartz filter into the growth tube,the number density of disoriented crystallites is effectively reduced owing to the improved spiral interaction.Furthermore,flexible Bi_2 Te_3 photoconductors are fabricated and exhibit strong near-infrared photoconductive response under different degrees of bending,which also confirms the obtained flexible 61 ms suitable for electronic applications.展开更多
Nickel(Ni)films with positive and negative textured surfaces of lotus and rice leaf patterns were fabricated through an inexpensive and effective method.The as-prepared Ni films were superhydrophobic and exhibited exc...Nickel(Ni)films with positive and negative textured surfaces of lotus and rice leaf patterns were fabricated through an inexpensive and effective method.The as-prepared Ni films were superhydrophobic and exhibited excellent tribological properties after chemical treatment.Experimental results indicated that the water contact angles(WCAs)on the surfaces of biomimetic textured Ni films(approximately 120°)were far greater than those on smooth films(65°).The biomimetic textured surfaces became superhydrophobic(WCA of approximately 150°)after perfluoropolyether(PFPE)treatment,which could be due to the combined effects of the special texture and the PFPE.The as-prepared biomimetic-textured Ni films modified with PFPE were improved with a low friction coefficient and excellent antiwear properties,which were due to the combination of the effective lubrication of PFPE and the special textures that served as a good lubricant and a debris reservoir.Moreover,the antiwear properties of the as-prepared Ni films with negative biomimetic microtextures modified with PFPE were much better than those of films with positive biomimetic microtextures modified with PFPE.展开更多
A type of Si-based blocked impurity band photoelectric detector with a planar architecture is designed and demonstrated by a modified silicon semiconductor processing technique.In this route,multiple ion implantation ...A type of Si-based blocked impurity band photoelectric detector with a planar architecture is designed and demonstrated by a modified silicon semiconductor processing technique.In this route,multiple ion implantation is utilized to ensure the uniform distribution of the P elements in silicon,and rapid thermal annealing treatment is used to activate the P atoms and reduce damages caused by ion-implantation.The fabricated prototype device exhibits an excellent photoelectric response performance.With a direct current(DC)bias voltage of-2.3 V,the device detectivity to blackbody irradiation is as high as 5×10^(13)cm·Hz^(1/2)/W,which corresponds to a device responsivity of nearly 4.6 A/W,showing their potential applications in infrared detection,infrared astrophysics,and extraterrestrial life science.In particular,the developed device preparation process is compatible with that for the CMOS-circuit,which greatly reduces the manufacturing cost.展开更多
High-energy Li-metal batteries (LMBs) suffer from short cycle life and safety issues due to severe parasitic reactions and dendrite growth of Li metal anode (LMA) in liquid electrolytes [1–3].It is generally believed...High-energy Li-metal batteries (LMBs) suffer from short cycle life and safety issues due to severe parasitic reactions and dendrite growth of Li metal anode (LMA) in liquid electrolytes [1–3].It is generally believed that replacing liquid electrolytes with solidstate electrolytes (SSEs) would be a feasible approach for practical LMBs [4,5]. Conventional SSEs including ceramic and polymer electrolytes have been studied for decades.展开更多
Based on the Landau-Dovenshire theory,the thermodynamic potential of(111) oriented films is constructed to investigate the pyroelectric properties of Pb(Zr_(1-x)Ti_x)O_3 thin films.Due to the presence of nonlinear cou...Based on the Landau-Dovenshire theory,the thermodynamic potential of(111) oriented films is constructed to investigate the pyroelectric properties of Pb(Zr_(1-x)Ti_x)O_3 thin films.Due to the presence of nonlinear coupling terms resulted from the(111) epitaxy with substrates,the effects of misfit strain and electric field on the phase transitions at room temperature are more complex than that of(001) and(110) oriented films.Pb(Zr_(1-x)Ti_x)O_3 thin films with the Ti composition around the morphotropic phase boundary(MPB) have the giant dielectric and pyroelectric properties.Moreover,Pb(Zr_(1-x)Ti_x)O_3 thin films grown on the tensile substrates which induce the triclinic γ phase have the larger dielectric and pyroelectric properties than that on the compressive substrates.Therefore,the physical properties of(111)oriented Pb(Zr_(1-x)Ti_x)O_3 thin films can be adjusted by choosing the suitable substrates.展开更多
Composition dependence of electrocaloric effect is investigated in(1- x)Pb(Mg1/3Nb2/3)O3- xP b Ti O3 single crystals by using an eighth-order Landau–Devonshire theory. The applied electric field along [001] direction...Composition dependence of electrocaloric effect is investigated in(1- x)Pb(Mg1/3Nb2/3)O3- xP b Ti O3 single crystals by using an eighth-order Landau–Devonshire theory. The applied electric field along [001] direction reduces the ferroelectric-ferroelectric phase transition temperatures, but increases the Curie temperatures. The electrocaloric coefficients of tetragonal phase are much larger than that of rhombohedral and monoclinic phase. A negative electrocaloric effect is observed near the MC-T phase transition in 0.69Pb(Mg1/3Nb2/3)O3-0.31 Pb Ti O3 single crystal. The application of a strong enough electric field results in a high adiabatic temperature change over a broad range of temperature.Therefore, it would be useful to construct a solid state cooling cycle over a broad temperature range for practical applications.展开更多
基金Funded by the National Natural Science Foundation of China(No.51371039)
文摘In order to study the effects of aging treatment on the intergranular corrosion(IGC) and stress corrosion cracking(SCC) of 7003 aluminum alloy(AA7003), the intergranular corrosion test, electrochemical test and slow strain rate test(SSRT), combined with optical microscopy(OM) and scanning electron microscopy(SEM) as well as transmission electron microscopy(TEM) observations have been carried out. The IGC and electrochemical test results showed that the IGC resistance of AA7003 for peak aged(PA) temper is the lowest, with double peak aged(DPA) the moderate, and retrogression and re-aging(RRA) the highest among three tempers, which is attributed to the continuous feature of precipitation on grain boundary of PA temper and the interrupted feature of precipitation on grain boundary of DPA and RRA tempers, as well as the wide precipitation free zones(PFZ) of RRA temper. In addition, the SSRT results indicated that all three tempers AA7003 are susceptible to SCC in IGC solution, and the change tendency of SCC susceptibility(ISCC) of AA7003 for three tempers follows the order: ISCC(RRA)<ISCC(DPA)<ISCC(PA).
基金Funded by the National Natural Science Foundation of China(No.51371039)
文摘The passive film-induced stress and the susceptibility to SCC of 7050 aluminum alloy in 3.5%sodium chloride solution at various pH values were investigated by slow strain rate testing(SSRT) and flowing stress differential method.The results showed that the passive film-induced stress and the susceptibility to SCC decreased with increasing pH values when pH≤7,while they increased with increasing pH values when pH>7.However,the corrosion type was interpreted as exfoliation corrosion when pH=l and 14,and there was no film formed on the surface of the specimens.The whole variation plots of film-induced stress and the SCC susceptibility with pH values were both presented as a valley shape.The symbol and amount of the film-induced stress were related to the compositions of the passive film,which were analyzed using X-ray photoelectron spectroscopy(XPS).
基金Funded by the National Natural Science Foundation of China(Nos.51271040 and 51271041)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘The effects of Mg on the microstructure and growth kinetics of the hot-dip Zn-22.3 Al-1.1 Si-x Mg(x = 0, 0.2, 0.4, and 0.6) coatings were investigated in detail. Scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction studies revealed the presence of η-Zn, α-Al, Zn/Al eutectoid,(Si), Al/Si eutectic, and Zn/Al/Mg_2 Zn11 ternary eutectic on the top surface of these Mg-containing coatings. Especially, a small amount of MgZn2 phase appears in top surface of Zn-22.3 Al-1.1 Si-0.6 Mg coating. Five phases are found in the alloy layers, i e, Fe_2 Al_5, FeAl_3, τ_(5C), τ_(5H), and τ_1. The addition of 0.2% Mg can delay the emergence of FeAl_3 phase. When the Mg content is more than 0.2%, the outer layers of coating change from τ_(5C) to τ_(5H) phase. The growth of the inhibition layer is diffusion controlled for various Mg content baths. Mg improves the corrosion resistance of the Mg-containing coatings, and the Zn-22.3 Al-1.1 Si-0.6 Mg coating possesses the highest protective properties.
基金Funded by the National Natural Science Foundation of China(Nos.51371039 and 51871031)
文摘Plasma electrolytic oxidation(PEO) coatings were fabricated on 6063 aluminum alloy in a cheap and convenient electrolyte. The effect of different current densities, i e, 5, 10, 15, and 20 A/dm^2 on the microstructure and corrosion behavior of coatings was comprehensively studied by scanning electron microscopy(SEM), stereoscopic microscopy, potentiodynamic polarization and electrochemical impedance spectroscopy(EIS), respectively. It is found that the pore density decreases and the pore size increases with increasing current density. The XRD results show that the coatings are only composed of α-Al_2 O_3 and γ-Al_2 O_3. Potentiodynamic polarization test proves that the coating formed under 10 A/dm^2 possesses the best anticorrosion property. The long time EIS test shows that the coating under 10 A/dm^2 is able to protect the aluminum alloy substrate after long time of immersion in 0.59 M NaCl solution, which confirms the salt solution immersion test results in 2 M NaCl solution.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61574038 and 61674038)the Natural Science Foundation of Fujian Province,China(Grant No.2014J05073)
文摘The effect of the deposition temperature of the buffer layer In_2S_3 on the band alignment of CZTS/In_2S_3 heterostructures and the solar cell performance have been investigated.The In_2S_3 films are prepared by thermal evaporation method at temperatures of 30,100,150,and 200 ℃,respectively.By using x-ray photoelectron spectroscopy(XPS),the valence band offsets(VBO) are determined to be-0.28 ±0.1,-0.28 ±0.1,-0.34 ±0.1,and-0.42 ±0.1 eV for the CZTS/In_2S_3heterostructures deposited at 30,100,150,and 200 ℃,respectively,and the corresponding conduction band offsets(CBO)are found to be 0.3 ±0.1,0.41 ±0.1,0.22±0.1,and 0.01 ±0.1 eV,respectively.The XPS study also reveals that interdiffusion of In and Cu occurs at the interface of the heterostructures,which is especially serious at 200 ℃ leading to large amount of interface defects or the formation of CuInS_2 phase at the interface.The CZTS solar cell with the buffer layer In_2S_3 deposited at 150 ℃ shows the best performance due to the proper CBO value at the heterostructure interface and the improved crystal quality of In_2S_3 film induced by the appropriate deposition temperature.The device prepared at 100 ℃presents the poorest performance owing to too high a value of CBO.It is demonstrated that the deposition temperature is a crucial parameter to control the quality of the solar cells.
基金Project supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,Chinathe Research Fund of Jiangsu Province Cultivation Base for State Key Laboratory of Photovoltaic Science and Technology,China+1 种基金Major Projects of Natural Science Research in Jiangsu Province,China(Grant No.15KJA43002)Qing Lan Project of Education Department of Jiangsu Province,China
文摘A phenomenological Landau–Devonshire theory is developed to investigate the ferroelectric, dielectric, and piezoelectric properties of(110) oriented Pb(Zr_(1-x)Ti_x)O_3(x = 0.4, 0.5, 0.6, and 0.7) thin films. At room temperature, the tetragonal a_1 phase, the orthorhombic a_2c phase, the triclinic γ_1 phase, and the triclinic γ_2 phase are stable. The appearance of the negative polarization component P_2 in the a_2c phase and the γ_1 phase is attributed to the nonlinear coupling terms in the thermodynamic potential. The γ phase of the Pb(Zr_(1-x)Ti_x)O_3 thin films has better dielectric and piezoelectric properties than the a_2c phase and the a_1 phase. The largest dielectric and piezoelectric coefficients are obtained in the Pb(Zr_(0.5)Ti_(0.5))O_3 thin film. The piezoelectric coefficient of 110–150 pm/V is obtained in the(110) oriented Pb(Zr_(0.5)Ti_(0.5))O_3 thin film, and the Pb(Zr_(0.3)Ti_(0.7))O_3 thin film has the remnant polarization and relative dielectric constant of 50 μC/cm^2 and 100, respectively,which are in agreement with the experimental measurements reported in the literature.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.62074036 and 61674038)the National Key Research and Development Program of China(Grant No.2016YFB0402303)。
文摘The helicity-dependent photoconductance of the edge states in three-dimensional topological insulator Bi_(2)Te_(3)films is investigated.It is revealed that the helicity-dependent photoconductivity current on the left edge of the Bi_(2)Te_(3)film shows an opposite sign with that on the right edge.In addition,the helicity-dependent photoconductivity current increases linearly with the applied longitudinal electric field,and it reverses the sign with the reversal of the electric field.As the thickness of the Bi_(2)Te_(3)film increases,the helicity-dependent photoconductivity current also increases.Theoretical analysis suggests that the helicity-dependent photo-conductivity current may come from the intrinsic spin orbit coupling(SOC)or the SOC introduced by the chiral impurities or defects.
基金Funded by National Natural Science Foundation of China(No.51371039)Zhejiang Provincial Natural Science Foundation of China(No.LGG18E020004)+1 种基金Open Foundation of Zhejiang Provincial Top Key Discipline of Mechanical EngineeringScience and Technology Project of Zhejiang Province(No.2015C37037)
文摘Plasma electrolytic oxidation(PEO) coatings were prepared on AZ31 magnesium alloy using alkaline phosphate as base electrolyte system, and with the addition of sodium silicate(Na_2SiO_3), sodium aluminate(NaAlO_2) and potassium fluorozirconate(K_2ZrF_6) as additives. The microstructure, phase composition and element composition as well as surface profile of the PEO coatings were analyzed by means of scanning electron microscopy(SEM), X-ray diffraction(XRD), energy dispersive X-ray spectroscopy(EDS), and threedimensional(3 D) optical profilometry. The corrosion and wear properties were evaluated by electrochemical potentiodynamic polarization in 3.5 wt% Na Cl solution and ball-on-disc wear tests, respectively. The results showed that the anions of the additives effectively participated in the coating formation influencing its microstructural features, chemical composition, corrosion resistance and tribological behaviour. It was observed that the sample treated by PEO in the electrolyte solution containing K_2ZrF_6 as an additive showed better corrosion and abrasive resistance.
基金Supported by the National Basic Research Program of China under Grant No 2012CB619200the National Natural Science Foundation of China under Grant Nos 61290304,11074265 and 11174307+1 种基金the Natural Science Foundation of Shanghai under Grant No 16ZR1441200the Frontier Science Research Project(Key Programs)of Chinese Academy of Sciences under Grant No QYZDJ-SSW-SLH018
文摘Recently,great efforts have been made in the fabrication of arbitrary warped devices to satisfy the requirement of wearable and lightweight electronic products.Direct growth of high crystalline quality films on flexible substrates is the most desirable method to fabricate flexible devices owing to the advantage of simple and compatible preparation technology with current semiconductor devices,while it is a very challenging work,and usually amorphous,polycrystalline or discontinuous single crystalline films are achieved.Here we demonstrate the direct growth of high-quality Bi_2 Te_3 single crystalline films on flexible polyimide substrates by the modified hot wall epitaxy technique.Experimental results reveal that adjacent crystallites are coherently coalesced to form a continuous film,although amounts of disoriented crystallites are generated due to fast growth rate.By inserting a quartz filter into the growth tube,the number density of disoriented crystallites is effectively reduced owing to the improved spiral interaction.Furthermore,flexible Bi_2 Te_3 photoconductors are fabricated and exhibit strong near-infrared photoconductive response under different degrees of bending,which also confirms the obtained flexible 61 ms suitable for electronic applications.
基金The authors appreciate the National Natural Science Foundation of China(Nos.51102028 and 51335002)acknowledge the financial support of the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Nickel(Ni)films with positive and negative textured surfaces of lotus and rice leaf patterns were fabricated through an inexpensive and effective method.The as-prepared Ni films were superhydrophobic and exhibited excellent tribological properties after chemical treatment.Experimental results indicated that the water contact angles(WCAs)on the surfaces of biomimetic textured Ni films(approximately 120°)were far greater than those on smooth films(65°).The biomimetic textured surfaces became superhydrophobic(WCA of approximately 150°)after perfluoropolyether(PFPE)treatment,which could be due to the combined effects of the special texture and the PFPE.The as-prepared biomimetic-textured Ni films modified with PFPE were improved with a low friction coefficient and excellent antiwear properties,which were due to the combination of the effective lubrication of PFPE and the special textures that served as a good lubricant and a debris reservoir.Moreover,the antiwear properties of the as-prepared Ni films with negative biomimetic microtextures modified with PFPE were much better than those of films with positive biomimetic microtextures modified with PFPE.
基金Projects(51371039,51871031)supported by the National Natural Science Foundation of ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China
基金the National Natural Science Foundation of China(Grant Nos.11933006,61805060,and 61290304).
文摘A type of Si-based blocked impurity band photoelectric detector with a planar architecture is designed and demonstrated by a modified silicon semiconductor processing technique.In this route,multiple ion implantation is utilized to ensure the uniform distribution of the P elements in silicon,and rapid thermal annealing treatment is used to activate the P atoms and reduce damages caused by ion-implantation.The fabricated prototype device exhibits an excellent photoelectric response performance.With a direct current(DC)bias voltage of-2.3 V,the device detectivity to blackbody irradiation is as high as 5×10^(13)cm·Hz^(1/2)/W,which corresponds to a device responsivity of nearly 4.6 A/W,showing their potential applications in infrared detection,infrared astrophysics,and extraterrestrial life science.In particular,the developed device preparation process is compatible with that for the CMOS-circuit,which greatly reduces the manufacturing cost.
基金the funding support from “Hundred Talents Program” of Zhejiang University and International Joint Laboratory of Chinese Education Ministry on Resource Chemistry at Shanghai Normal Universitythe National Natural Science Foundation of China (No. 91961126) for funding this work。
文摘High-energy Li-metal batteries (LMBs) suffer from short cycle life and safety issues due to severe parasitic reactions and dendrite growth of Li metal anode (LMA) in liquid electrolytes [1–3].It is generally believed that replacing liquid electrolytes with solidstate electrolytes (SSEs) would be a feasible approach for practical LMBs [4,5]. Conventional SSEs including ceramic and polymer electrolytes have been studied for decades.
基金Supported by the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe research fund of Jiangsu Province Cultivation base for State Key Laboratory of Photovoltaic Science and Technology+1 种基金Major Projects of Natural Science Research in Jiangsu Province under Grant Nos.15KJA43002,16KJD430006sponsored by Qing Lan Project of Education Department of Jiangsu Province
文摘Based on the Landau-Dovenshire theory,the thermodynamic potential of(111) oriented films is constructed to investigate the pyroelectric properties of Pb(Zr_(1-x)Ti_x)O_3 thin films.Due to the presence of nonlinear coupling terms resulted from the(111) epitaxy with substrates,the effects of misfit strain and electric field on the phase transitions at room temperature are more complex than that of(001) and(110) oriented films.Pb(Zr_(1-x)Ti_x)O_3 thin films with the Ti composition around the morphotropic phase boundary(MPB) have the giant dielectric and pyroelectric properties.Moreover,Pb(Zr_(1-x)Ti_x)O_3 thin films grown on the tensile substrates which induce the triclinic γ phase have the larger dielectric and pyroelectric properties than that on the compressive substrates.Therefore,the physical properties of(111)oriented Pb(Zr_(1-x)Ti_x)O_3 thin films can be adjusted by choosing the suitable substrates.
基金Supported by the State Key Program of National Natural Science of China under Grant No.51335002Changzhou Science and Technology Project under Grant No.CJ20130022the Priority Academic Program Development of Jiangsu Higher Education Institutions on Renewable Energy Material Science and Engineering
文摘Composition dependence of electrocaloric effect is investigated in(1- x)Pb(Mg1/3Nb2/3)O3- xP b Ti O3 single crystals by using an eighth-order Landau–Devonshire theory. The applied electric field along [001] direction reduces the ferroelectric-ferroelectric phase transition temperatures, but increases the Curie temperatures. The electrocaloric coefficients of tetragonal phase are much larger than that of rhombohedral and monoclinic phase. A negative electrocaloric effect is observed near the MC-T phase transition in 0.69Pb(Mg1/3Nb2/3)O3-0.31 Pb Ti O3 single crystal. The application of a strong enough electric field results in a high adiabatic temperature change over a broad range of temperature.Therefore, it would be useful to construct a solid state cooling cycle over a broad temperature range for practical applications.
