Conductivities of Langmuir-Blodgett(LB) films of tetrabenzylthio- tetra-thiafulvalence-Ni(dmit)_2/stearic acid (SA)were described. This charge transfer complex was transferred with SA onto a glass plate coated with A1...Conductivities of Langmuir-Blodgett(LB) films of tetrabenzylthio- tetra-thiafulvalence-Ni(dmit)_2/stearic acid (SA)were described. This charge transfer complex was transferred with SA onto a glass plate coated with A1 electrodes. The relation of conductivities of LB films with molar ratio of SA was studied. The conductivities of LB films of TBT-TTF-Ni(dmit)_2/SA were measured under undoped and I_2 doped states. The maximum conductivity () of LB film was 40s/cm.展开更多
Monolayer formation and LB film fabrication of amphiphilic derivative of biliverdin 1, diododecyl biliverdinamide [B(CONHC12H25)(2), 2] at an air-water interface on pure water subphase and subphase containing calcium ...Monolayer formation and LB film fabrication of amphiphilic derivative of biliverdin 1, diododecyl biliverdinamide [B(CONHC12H25)(2), 2] at an air-water interface on pure water subphase and subphase containing calcium ion were investigated and compared with 1. The coordination in ordered molecular films is much different from that in bulk solution. The formation of ligand-calcium complex was confirmed by X-ray photoelectron spectroscopy.展开更多
1,1,4,4-Tetraphenyl-1,3-butadiene (TPB) was successfully introduced into the polymer multilayer films by means of Langmuir-Blodgett (LB) technique. Results of UV-VIS spectra and X-ray diffraction showed that the unifo...1,1,4,4-Tetraphenyl-1,3-butadiene (TPB) was successfully introduced into the polymer multilayer films by means of Langmuir-Blodgett (LB) technique. Results of UV-VIS spectra and X-ray diffraction showed that the uniform films had a layer structure similar to the superlattice of organic multiple quantum wells. The electroluminescence (EL) devices fabricated from the doped polymer LB films emitted blue light. Compared with the casting films, the photoluminescence (PL) and EL spectra showed that the exciton energy shifts to higher and the half-width of the emission peak becomes narrower due to exciton confinement effect.展开更多
Langmuir-Blodgett(LB)films of tetra-nonyl phthalocyanine copper (TNPcCu)were prepared.Molecular arrangement and orientation of these films were studied in detail.LB multilayer films of TNPcCu show a very Strong x-ray ...Langmuir-Blodgett(LB)films of tetra-nonyl phthalocyanine copper (TNPcCu)were prepared.Molecular arrangement and orientation of these films were studied in detail.LB multilayer films of TNPcCu show a very Strong x-ray diffration peak and two weak peaks which indicate that the LB films form a quasi-crystal structure which molecules are arranged orderly.IR reflection absorption spectra and polarized VIS absorption spectra not only confirm the previous result but also indicate that phthalocyanine rings orient nearly perpendicular to the substrate surface and perpendicular to the lifting direction and the side-chain segments are not preferred oriented.展开更多
Nanoscale hybrid organic/inorganic Langmuir-Blodgett films of cerium-substituted heteropolymolybdates(Ce-HPMo) and π-conjugated macromolecule poly(1,2-dihydro-2,2,4-trimethyl)quinoline(PQ) were obtained with auxiliar...Nanoscale hybrid organic/inorganic Langmuir-Blodgett films of cerium-substituted heteropolymolybdates(Ce-HPMo) and π-conjugated macromolecule poly(1,2-dihydro-2,2,4-trimethyl)quinoline(PQ) were obtained with auxiliary film-forming material stearic acid(SA) or octadecylamine(ODA). The surface pressure-area isotherms illuminate the formation of the hybrid LB films of PQ/ODA/Ce-HPMo and PQ/SA/Ce-HPMo. The different film-forming mechanism was discussed when the different auxiliary film-forming materials were used in the system. The absorption spectra indicate that the molecules of PQ and Ce-HPMo are incorporated into the LB films. Tapping-mode AFM image reveals a granular surface texture of nanosized Ce-substituted heteropolymolybdate. STM image shows that the conductivity is greatly improved after Ce-substituted heteropolymolybdates are incorporated in the films.展开更多
Interlayer energy transfer between 2, 3-naphtho-10-hexadecylaza-15-crown-5 (NC16) and N-[1-(9-methoxyanthryl)]decylaza-15-crown-5 (A10C) within multilayer Langmuir-Blodgett films has been studied by steady-state fluor...Interlayer energy transfer between 2, 3-naphtho-10-hexadecylaza-15-crown-5 (NC16) and N-[1-(9-methoxyanthryl)]decylaza-15-crown-5 (A10C) within multilayer Langmuir-Blodgett films has been studied by steady-state fluorescence spectra. The donor and acceptor could be separated precisely by inserting stearic acid (SA) spacers. The efficiency of the energy transfer increases with the decrease in the donor-acceptor distance by a quadratic manner, suggesting the donor excitations are delocalized in the layer.展开更多
The characteristics of the LB films of Schiff base aluminium(Ⅲ), tris(2-hydroxy-5-nitro-N-dodecyl-benzylideneaminato) aluminium(Ⅲ)[Al(TA12)_3], were studied. The surface pressure-area(π-A) isotherm of Al(TA12)_3 in...The characteristics of the LB films of Schiff base aluminium(Ⅲ), tris(2-hydroxy-5-nitro-N-dodecyl-benzylideneaminato) aluminium(Ⅲ)[Al(TA12)_3], were studied. The surface pressure-area(π-A) isotherm of Al(TA12)_3 in the pure water subphase was investigated. The molecular area, 0.48 nm^2, is one-third of the expected value that indicates the formation of an aggregate. The Langmuir-Blodgett(LB) films of Al(TA12)_3 were transferred and characterized. The UV-Vis spectra and the AFM image both confirmed that the J-aggregates formed. The polarized UV-Vis spectra indicated that the complex plane had to be oriented with an angle of about 30° to the substrate surface. The IR spectra suggested that the complexation took place between aluminium ions and the oxygen atoms of the ligand rather than the nitrogen atom.展开更多
The interfacial behaviors of the non-typical amphiphilic compound p-methylphenylazocalix[4]arene 1 and p-chlorophenylazocalix[4]arene 2 at the air/water interface and photochromism in the Langmuir-Blodgett films were ...The interfacial behaviors of the non-typical amphiphilic compound p-methylphenylazocalix[4]arene 1 and p-chlorophenylazocalix[4]arene 2 at the air/water interface and photochromism in the Langmuir-Blodgett films were studied by surface pressure-area isotherm and UV-Vis spectra. The results indicate that they can form stable monolayers at the air / water interface although they have no hydrophobic alkyl chains, and their LB film underwent reversible trans-cis photoisomerization on UV and daylight illumination.展开更多
This study investigated the behavior and molecular organization of synthetic artificial mimic molecules that resemble the following tetraether lipids: di-O-hexadecyl-glycero-3-phosphatidyl-glycerol (DHGPG) and bis-4-d...This study investigated the behavior and molecular organization of synthetic artificial mimic molecules that resemble the following tetraether lipids: di-O-hexadecyl-glycero-3-phosphatidyl-glycerol (DHGPG) and bis-4-dodecylphenyl-12-phosphate. These molecules were analyzed using Langmuir film balance, ellipsometry and atomic force microscopy. The monolayer Langmuir-Blodgett films of DHGPG and bis-4-dodecylphenyl-12-phosphate were stable on the solid surface silicon wafers. The ellipsometry and AFM results showed that monolayers Langmuir-Blodgett films of DHGPG and bis-4-dodecylphenyl-12-phosphate were present, and the thickness of the observed films varied from 1.2 - 5.0 nm.展开更多
The ring patterns of calcium oxalate crystals were induced by domains in Langmuir-Blodgett (LB) films of dipalmitoylpho- sphatidylcboline (DPPC). The result was explained by the defects at the ring boundaries of l...The ring patterns of calcium oxalate crystals were induced by domains in Langmuir-Blodgett (LB) films of dipalmitoylpho- sphatidylcboline (DPPC). The result was explained by the defects at the ring boundaries of liquid condensed (LC) and liquid expanded (LE) phases of LB film. These boundaries could provide less free energy and much more nucleating sites for COM crystals.展开更多
Mixed Stearic acid and poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) Langmuir- Blodgett(LB) films were successfully fabricated by the conventional vertical dipping method.Stearic acid and PEDOT...Mixed Stearic acid and poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) Langmuir- Blodgett(LB) films were successfully fabricated by the conventional vertical dipping method.Stearic acid and PEDOT/PSS was dissolved in chloroform and spread on subphase containing 0.04wt% FeCl_3.Conductive Y-type mixed LB films was successfully prepared under the condition of surface pressure with 30 mN/m,pH 3.8,and 19℃.UV-VIS spectrum showed that well ordered layer-by-layer fabrication of mixed films were obtained and thickness of single layer film with about 5 nm was evaluated.The morphology image of mixed LB film was observed by atomic force microscopy (AFM).The conductivity of mixed LB film was about 1.8×10^(-5)S/cm and the film showed sensitivity to NH_3 at the same time.展开更多
Ultra-thin (20-100nm) polymethylmethacrylate(PMMA) films prepared by Langmuir-Blodgett techniques have been explored as high resolution electron beam resists. A Hitachi S-450 Scanning Electron Microscope (SEM) has bee...Ultra-thin (20-100nm) polymethylmethacrylate(PMMA) films prepared by Langmuir-Blodgett techniques have been explored as high resolution electron beam resists. A Hitachi S-450 Scanning Electron Microscope (SEM) has been refitted for a high resolution electron beam exposure system. The lithographic properties and exposure conditions of LB PMMA films were investigated. 0.15μm lines-and-spaces patterns were achieved by using the SEM as the exposure tool. The results demonstrate that the etch resistance of such films is sufficiently good to allow patterning of a 20 nm aluminum film suitable for mask fabrication.展开更多
The molecular aggregation, orientation, and structure in Langmuir-Blodgett films of ferroelectric liquid crystal were studied by ultraviolet and Fourier transform infrared spectra. The results show that medium strong ...The molecular aggregation, orientation, and structure in Langmuir-Blodgett films of ferroelectric liquid crystal were studied by ultraviolet and Fourier transform infrared spectra. The results show that medium strong (H-aggregates) in the Langmuir-Blodgett films of ferroelectric liquid crystal are formed by chromophores where the alkyl chains are nearly perpendicular to the film surface. Compared with the cast films, the CO stretching bands, due to the rotational isomerism around the O—C axis of the chiral part, can be identified clearly in Langmuir-Blodgett films.展开更多
It has been shown by thermodynamic and electro-chemical methods that coordination interactions are involved in the process of incorporation of rare-earth elements and/or Fe into Langmuir monolayers of oligomer with al...It has been shown by thermodynamic and electro-chemical methods that coordination interactions are involved in the process of incorporation of rare-earth elements and/or Fe into Langmuir monolayers of oligomer with alkyl fragment. A coordination mechanism, which is responsible for self-organization of octahedral Fe(II)-complexes of nano-cyclic ligands obtained from oligomer of thiophene pyrrole series derivatives in compressed Langmuir monolayers has been proposed. It has been established that a coordinational-polymeric hexagonal network of nano-cyclic ligands with metal centers is formed at the phase transition when compressing the Langmuir monolayers of thiophene pyrrole series oligomer with alkyl fragment on surface of subphase with rare-earth (Sm, Er, Ce) and/or Fe ions.展开更多
The Langmuir-Blodgett(LB)films of tetra-lauryl chloroaluminum phthalocyanine(TLAlCIPc)and a 1:1 mixture of TLAlCIPc and stearyl alcohol(SA)were prepared.The Raman spectrum of solid TLAlCIPc in KBr pellet was investiga...The Langmuir-Blodgett(LB)films of tetra-lauryl chloroaluminum phthalocyanine(TLAlCIPc)and a 1:1 mixture of TLAlCIPc and stearyl alcohol(SA)were prepared.The Raman spectrum of solid TLAlCIPc in KBr pellet was investigated.All the Raman lines were assigned.The surface-enhanced resonance Raman spectra of the LB films deposited on the silver island film that were vacuum-deposited on glass slides have been observed.展开更多
The regeneration procedure of Q-state PbS particles in lead arachidate(PbAr)Langmuir-Blodgett films have been studied by means of UV-vis absorption, FT-IR spectra and quartz crystal microbalance(QCM) measurements.The ...The regeneration procedure of Q-state PbS particles in lead arachidate(PbAr)Langmuir-Blodgett films have been studied by means of UV-vis absorption, FT-IR spectra and quartz crystal microbalance(QCM) measurements.The results showed that the mole fraction of PbS particles in LB films was increased by immersing PbScontaining ArH LB films in a Pb ̄(2+) buffer solution,followed by being reexposed to H_2S gas.展开更多
Exploring dimensionality effects on cuprates is important for understanding the nature of high-temperature superconductivity.By atomically layer-by-layer growth with oxide molecular beam epitaxy,we demonstrate that La...Exploring dimensionality effects on cuprates is important for understanding the nature of high-temperature superconductivity.By atomically layer-by-layer growth with oxide molecular beam epitaxy,we demonstrate that La_(2−x)Sr_(x)CuO_(4)(x=0.15)thin films remain superconducting down to 2 unit cells of thickness but quickly reach the maximum superconducting transition temperature at and above 4 unit cells.By fitting the critical magnetic field(μ0H_(c2)),we show that the anisotropy of the film’s superconductivity increases with decreasing film thickness,indicating that the superconductivity of the film gradually evolves from weak three-to two-dimensional character.These results are helpful to gain more insight into the nature of high-temperature superconductivity with dimensionality.展开更多
The high efficiency,solution processibility,and flexibility of perovskite solar cells make them promising candidates for the photovoltaic industry[1−8].The deposition method is one of the most critical factors that af...The high efficiency,solution processibility,and flexibility of perovskite solar cells make them promising candidates for the photovoltaic industry[1−8].The deposition method is one of the most critical factors that affect the performance of perovskite films.Various deposition methods have been developed to make perovskite films,including spin-coating,slotdie coating.展开更多
Pure cobalt(Co)thin films were fabricated by direct current magnetron sputtering,and the effects of sputtering power and pres-sure on the microstructure and electromagnetic properties of the films were investigated.As...Pure cobalt(Co)thin films were fabricated by direct current magnetron sputtering,and the effects of sputtering power and pres-sure on the microstructure and electromagnetic properties of the films were investigated.As the sputtering power increases from 15 to 60 W,the Co thin films transition from an amorphous to a polycrystalline state,accompanied by an increase in the intercrystal pore width.Simultaneously,the resistivity decreases from 276 to 99μΩ·cm,coercivity increases from 162 to 293 Oe,and in-plane magnetic aniso-tropy disappears.As the sputtering pressure decreases from 1.6 to 0.2 Pa,grain size significantly increases,resistivity significantly de-creases,and the coercivity significantly increases(from 67 to 280 Oe),which can be attributed to the increase in defect width.Corres-pondingly,a quantitative model for the coercivity of Co thin films was formulated.The polycrystalline films sputtered under pressures of 0.2 and 0.4 Pa exhibit significant in-plane magnetic anisotropy,which is primarily attributable to increased microstress.展开更多
文摘Conductivities of Langmuir-Blodgett(LB) films of tetrabenzylthio- tetra-thiafulvalence-Ni(dmit)_2/stearic acid (SA)were described. This charge transfer complex was transferred with SA onto a glass plate coated with A1 electrodes. The relation of conductivities of LB films with molar ratio of SA was studied. The conductivities of LB films of TBT-TTF-Ni(dmit)_2/SA were measured under undoped and I_2 doped states. The maximum conductivity () of LB film was 40s/cm.
文摘Monolayer formation and LB film fabrication of amphiphilic derivative of biliverdin 1, diododecyl biliverdinamide [B(CONHC12H25)(2), 2] at an air-water interface on pure water subphase and subphase containing calcium ion were investigated and compared with 1. The coordination in ordered molecular films is much different from that in bulk solution. The formation of ligand-calcium complex was confirmed by X-ray photoelectron spectroscopy.
基金This Project is financially supported by the National Natural Science Foundation of China
文摘1,1,4,4-Tetraphenyl-1,3-butadiene (TPB) was successfully introduced into the polymer multilayer films by means of Langmuir-Blodgett (LB) technique. Results of UV-VIS spectra and X-ray diffraction showed that the uniform films had a layer structure similar to the superlattice of organic multiple quantum wells. The electroluminescence (EL) devices fabricated from the doped polymer LB films emitted blue light. Compared with the casting films, the photoluminescence (PL) and EL spectra showed that the exciton energy shifts to higher and the half-width of the emission peak becomes narrower due to exciton confinement effect.
文摘Langmuir-Blodgett(LB)films of tetra-nonyl phthalocyanine copper (TNPcCu)were prepared.Molecular arrangement and orientation of these films were studied in detail.LB multilayer films of TNPcCu show a very Strong x-ray diffration peak and two weak peaks which indicate that the LB films form a quasi-crystal structure which molecules are arranged orderly.IR reflection absorption spectra and polarized VIS absorption spectra not only confirm the previous result but also indicate that phthalocyanine rings orient nearly perpendicular to the substrate surface and perpendicular to the lifting direction and the side-chain segments are not preferred oriented.
文摘Nanoscale hybrid organic/inorganic Langmuir-Blodgett films of cerium-substituted heteropolymolybdates(Ce-HPMo) and π-conjugated macromolecule poly(1,2-dihydro-2,2,4-trimethyl)quinoline(PQ) were obtained with auxiliary film-forming material stearic acid(SA) or octadecylamine(ODA). The surface pressure-area isotherms illuminate the formation of the hybrid LB films of PQ/ODA/Ce-HPMo and PQ/SA/Ce-HPMo. The different film-forming mechanism was discussed when the different auxiliary film-forming materials were used in the system. The absorption spectra indicate that the molecules of PQ and Ce-HPMo are incorporated into the LB films. Tapping-mode AFM image reveals a granular surface texture of nanosized Ce-substituted heteropolymolybdate. STM image shows that the conductivity is greatly improved after Ce-substituted heteropolymolybdates are incorporated in the films.
基金Financial support fron he National Key Project on Fundamental Research and Development(Grant No.G2000078104 and G2000077502)the National Natural Science Foundation of China is grateful
文摘Interlayer energy transfer between 2, 3-naphtho-10-hexadecylaza-15-crown-5 (NC16) and N-[1-(9-methoxyanthryl)]decylaza-15-crown-5 (A10C) within multilayer Langmuir-Blodgett films has been studied by steady-state fluorescence spectra. The donor and acceptor could be separated precisely by inserting stearic acid (SA) spacers. The efficiency of the energy transfer increases with the decrease in the donor-acceptor distance by a quadratic manner, suggesting the donor excitations are delocalized in the layer.
基金Supported by the National Natural Science Foundation of China(No. 29973026, 20073016).
文摘The characteristics of the LB films of Schiff base aluminium(Ⅲ), tris(2-hydroxy-5-nitro-N-dodecyl-benzylideneaminato) aluminium(Ⅲ)[Al(TA12)_3], were studied. The surface pressure-area(π-A) isotherm of Al(TA12)_3 in the pure water subphase was investigated. The molecular area, 0.48 nm^2, is one-third of the expected value that indicates the formation of an aggregate. The Langmuir-Blodgett(LB) films of Al(TA12)_3 were transferred and characterized. The UV-Vis spectra and the AFM image both confirmed that the J-aggregates formed. The polarized UV-Vis spectra indicated that the complex plane had to be oriented with an angle of about 30° to the substrate surface. The IR spectra suggested that the complexation took place between aluminium ions and the oxygen atoms of the ligand rather than the nitrogen atom.
基金supported by the National Natural Science Foundation(Grant No.20372032)Jiangsu Province in China(Grant.No.BK2004085)
文摘The interfacial behaviors of the non-typical amphiphilic compound p-methylphenylazocalix[4]arene 1 and p-chlorophenylazocalix[4]arene 2 at the air/water interface and photochromism in the Langmuir-Blodgett films were studied by surface pressure-area isotherm and UV-Vis spectra. The results indicate that they can form stable monolayers at the air / water interface although they have no hydrophobic alkyl chains, and their LB film underwent reversible trans-cis photoisomerization on UV and daylight illumination.
文摘This study investigated the behavior and molecular organization of synthetic artificial mimic molecules that resemble the following tetraether lipids: di-O-hexadecyl-glycero-3-phosphatidyl-glycerol (DHGPG) and bis-4-dodecylphenyl-12-phosphate. These molecules were analyzed using Langmuir film balance, ellipsometry and atomic force microscopy. The monolayer Langmuir-Blodgett films of DHGPG and bis-4-dodecylphenyl-12-phosphate were stable on the solid surface silicon wafers. The ellipsometry and AFM results showed that monolayers Langmuir-Blodgett films of DHGPG and bis-4-dodecylphenyl-12-phosphate were present, and the thickness of the observed films varied from 1.2 - 5.0 nm.
基金This research work was granted by the National Natural Science Foundation of China(No.20471024).
文摘The ring patterns of calcium oxalate crystals were induced by domains in Langmuir-Blodgett (LB) films of dipalmitoylpho- sphatidylcboline (DPPC). The result was explained by the defects at the ring boundaries of liquid condensed (LC) and liquid expanded (LE) phases of LB film. These boundaries could provide less free energy and much more nucleating sites for COM crystals.
文摘Mixed Stearic acid and poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) Langmuir- Blodgett(LB) films were successfully fabricated by the conventional vertical dipping method.Stearic acid and PEDOT/PSS was dissolved in chloroform and spread on subphase containing 0.04wt% FeCl_3.Conductive Y-type mixed LB films was successfully prepared under the condition of surface pressure with 30 mN/m,pH 3.8,and 19℃.UV-VIS spectrum showed that well ordered layer-by-layer fabrication of mixed films were obtained and thickness of single layer film with about 5 nm was evaluated.The morphology image of mixed LB film was observed by atomic force microscopy (AFM).The conductivity of mixed LB film was about 1.8×10^(-5)S/cm and the film showed sensitivity to NH_3 at the same time.
文摘Ultra-thin (20-100nm) polymethylmethacrylate(PMMA) films prepared by Langmuir-Blodgett techniques have been explored as high resolution electron beam resists. A Hitachi S-450 Scanning Electron Microscope (SEM) has been refitted for a high resolution electron beam exposure system. The lithographic properties and exposure conditions of LB PMMA films were investigated. 0.15μm lines-and-spaces patterns were achieved by using the SEM as the exposure tool. The results demonstrate that the etch resistance of such films is sufficiently good to allow patterning of a 20 nm aluminum film suitable for mask fabrication.
基金Project(2004CB619301) supported by the National Key Fundamental Research and Development Program of China
文摘The molecular aggregation, orientation, and structure in Langmuir-Blodgett films of ferroelectric liquid crystal were studied by ultraviolet and Fourier transform infrared spectra. The results show that medium strong (H-aggregates) in the Langmuir-Blodgett films of ferroelectric liquid crystal are formed by chromophores where the alkyl chains are nearly perpendicular to the film surface. Compared with the cast films, the CO stretching bands, due to the rotational isomerism around the O—C axis of the chiral part, can be identified clearly in Langmuir-Blodgett films.
文摘It has been shown by thermodynamic and electro-chemical methods that coordination interactions are involved in the process of incorporation of rare-earth elements and/or Fe into Langmuir monolayers of oligomer with alkyl fragment. A coordination mechanism, which is responsible for self-organization of octahedral Fe(II)-complexes of nano-cyclic ligands obtained from oligomer of thiophene pyrrole series derivatives in compressed Langmuir monolayers has been proposed. It has been established that a coordinational-polymeric hexagonal network of nano-cyclic ligands with metal centers is formed at the phase transition when compressing the Langmuir monolayers of thiophene pyrrole series oligomer with alkyl fragment on surface of subphase with rare-earth (Sm, Er, Ce) and/or Fe ions.
文摘The Langmuir-Blodgett(LB)films of tetra-lauryl chloroaluminum phthalocyanine(TLAlCIPc)and a 1:1 mixture of TLAlCIPc and stearyl alcohol(SA)were prepared.The Raman spectrum of solid TLAlCIPc in KBr pellet was investigated.All the Raman lines were assigned.The surface-enhanced resonance Raman spectra of the LB films deposited on the silver island film that were vacuum-deposited on glass slides have been observed.
文摘The regeneration procedure of Q-state PbS particles in lead arachidate(PbAr)Langmuir-Blodgett films have been studied by means of UV-vis absorption, FT-IR spectra and quartz crystal microbalance(QCM) measurements.The results showed that the mole fraction of PbS particles in LB films was increased by immersing PbScontaining ArH LB films in a Pb ̄(2+) buffer solution,followed by being reexposed to H_2S gas.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1403000)the Na-tional Natural Science Foundation of China(Grant No.12250710675).
文摘Exploring dimensionality effects on cuprates is important for understanding the nature of high-temperature superconductivity.By atomically layer-by-layer growth with oxide molecular beam epitaxy,we demonstrate that La_(2−x)Sr_(x)CuO_(4)(x=0.15)thin films remain superconducting down to 2 unit cells of thickness but quickly reach the maximum superconducting transition temperature at and above 4 unit cells.By fitting the critical magnetic field(μ0H_(c2)),we show that the anisotropy of the film’s superconductivity increases with decreasing film thickness,indicating that the superconductivity of the film gradually evolves from weak three-to two-dimensional character.These results are helpful to gain more insight into the nature of high-temperature superconductivity with dimensionality.
基金We thank the National Natural Science Foundation of China(52203217 and 21961160720)the National Key Research and Development Program of China(2022YFB3803300)the open research fund of Songshan Lake Materials Laboratory(2021SLABFK02)for financial support.
文摘The high efficiency,solution processibility,and flexibility of perovskite solar cells make them promising candidates for the photovoltaic industry[1−8].The deposition method is one of the most critical factors that affect the performance of perovskite films.Various deposition methods have been developed to make perovskite films,including spin-coating,slotdie coating.
基金the financial support from the National Key Research and Development Program of China(No.2017YFB0305500)the State Key Laboratory of Powder Metallurgy,Central South University,Changsha,China.
文摘Pure cobalt(Co)thin films were fabricated by direct current magnetron sputtering,and the effects of sputtering power and pres-sure on the microstructure and electromagnetic properties of the films were investigated.As the sputtering power increases from 15 to 60 W,the Co thin films transition from an amorphous to a polycrystalline state,accompanied by an increase in the intercrystal pore width.Simultaneously,the resistivity decreases from 276 to 99μΩ·cm,coercivity increases from 162 to 293 Oe,and in-plane magnetic aniso-tropy disappears.As the sputtering pressure decreases from 1.6 to 0.2 Pa,grain size significantly increases,resistivity significantly de-creases,and the coercivity significantly increases(from 67 to 280 Oe),which can be attributed to the increase in defect width.Corres-pondingly,a quantitative model for the coercivity of Co thin films was formulated.The polycrystalline films sputtered under pressures of 0.2 and 0.4 Pa exhibit significant in-plane magnetic anisotropy,which is primarily attributable to increased microstress.