The corrosion resistance of electroless Ni-P deposits with phosphorous contents from 12% to 14% in sodium chloride solutions was studied. The deposits were immersed in 3.5% NaCl solutions for 29 d to obtain the electr...The corrosion resistance of electroless Ni-P deposits with phosphorous contents from 12% to 14% in sodium chloride solutions was studied. The deposits were immersed in 3.5% NaCl solutions for 29 d to obtain the electrochemical parameters and were examined in a standard salt spray test for 15 d respectively. The corrosion resistance of the deposits was studied by poten- tio-dynamic scan, electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD) and cold-field emission scanning electron microscopy (FE-SEM) equipped with an energy dispersive X-ray detector (EDX). The patterns of XRD and the results of FE-SEM showed that the prepared deposits were amorphous. But after a 15 d standard salt spray test, a few pinholes appeared on the surface of the deposit and the weight content of phosphorus on the surface of the deposit was higher (which was beneficial to the formation of the passivation films) than that before the standard salt spray test when the nickel content was lower because the dissolved weight of nickel was greater than that of phosphorus. The results from potentio-dynamic scan and EIS showed that passivation films formed on the Ni-P deposit after immersion in the NaCl solutions, which decreased the corrosion rate of Ni-P samples. The results of this work show their potential applications in marine corrosion.展开更多
A systematic study of the effect of microstructure on the EL properties of ZnS:Er thin film devices fabricated by thermal evaporatio n was carried out using XRD, XPS and EL techniques. The experimental results i ndica...A systematic study of the effect of microstructure on the EL properties of ZnS:Er thin film devices fabricated by thermal evaporatio n was carried out using XRD, XPS and EL techniques. The experimental results i ndicate that the high brightness of the devices is attributed to the deposition growth of cr ystallites oriented in the (311), (400) directions. This can be explained by ass uming a higher population of erbium being in the trivalent charge state in the ( 311), (400) planes of the films grown under certain deposition condition. It is concluded that only the part of rare earth dopant being in trivalent charge stat e in the film contributes to luminescence. The mechanism of the formation of lum inescence center and the excitation of Er 3+ ion by the electric field are discussed.展开更多
文摘The corrosion resistance of electroless Ni-P deposits with phosphorous contents from 12% to 14% in sodium chloride solutions was studied. The deposits were immersed in 3.5% NaCl solutions for 29 d to obtain the electrochemical parameters and were examined in a standard salt spray test for 15 d respectively. The corrosion resistance of the deposits was studied by poten- tio-dynamic scan, electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD) and cold-field emission scanning electron microscopy (FE-SEM) equipped with an energy dispersive X-ray detector (EDX). The patterns of XRD and the results of FE-SEM showed that the prepared deposits were amorphous. But after a 15 d standard salt spray test, a few pinholes appeared on the surface of the deposit and the weight content of phosphorus on the surface of the deposit was higher (which was beneficial to the formation of the passivation films) than that before the standard salt spray test when the nickel content was lower because the dissolved weight of nickel was greater than that of phosphorus. The results from potentio-dynamic scan and EIS showed that passivation films formed on the Ni-P deposit after immersion in the NaCl solutions, which decreased the corrosion rate of Ni-P samples. The results of this work show their potential applications in marine corrosion.
文摘A systematic study of the effect of microstructure on the EL properties of ZnS:Er thin film devices fabricated by thermal evaporatio n was carried out using XRD, XPS and EL techniques. The experimental results i ndicate that the high brightness of the devices is attributed to the deposition growth of cr ystallites oriented in the (311), (400) directions. This can be explained by ass uming a higher population of erbium being in the trivalent charge state in the ( 311), (400) planes of the films grown under certain deposition condition. It is concluded that only the part of rare earth dopant being in trivalent charge stat e in the film contributes to luminescence. The mechanism of the formation of lum inescence center and the excitation of Er 3+ ion by the electric field are discussed.
